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FAQs about Overflows, Bulkheads/Through-puts, Stand-Pipes, Holes vs. Boxes... Sizing, Number, Placement 5

Related Articles: Overflow Box Arrangements, Plumbing Marine Systems by Bob Fenner, Myth of the One Inch Beast (Why Relying on One Inch Overflows... or Overflow! Is foolhardy) by Scott Vallembois, The Flowrates through various Bulkheads (In relation to overflow drains) by Scott Vallembois, Plumbing Return Manifolds, Refugiums

Related FAQs: Through Puts Placement/Number/Size 1, Through-Puts 2,   Through-Put Sizing/Number/Placement 3, Through-Put Sizing/Number/Placement 4, Through-Put Sizing/Number/Placement 6, & Overflows 1, Overflows 2, Overflows 3, Overflows 4, & FAQs on: Rationale/Use, Through-Hull Fittings, Hang-On Selection, Plumbing, Troubleshooting/Repair... Marine Plumbing 1, Marine Plumbing 2, Marine Plumbing 3Marine Plumbing 4, Marine Plumbing 5, Marine Plumbing 6, Plumbing 7, Plumbing 8, Plumbing 9, Plumbing 10, Plumbing 11, Plumbing 12, Plumbing 13, Plumbing 14, Plumbing 15, Plumbing 16, Plumbing 17, Plumbing 18, Holes & Drilling, Durso Standpipes, Make Up Water Systems, Pumps, Plumbing, Circulation, Sumps, RefugiumsMarine Circulation 2, Gear Selection for Circulation, Pump Problems Fish-Only Marine Set-ups, Fish-Only Marine Systems 2, FOWLR/Fish and Invertebrate Systems, Reef Systems, Coldwater Systems, Small Systems, Large SystemsWater Changes Surge Devices

Top view overflow tower

Re: 220 gallon Overflows & Returns - 5/23/10
Thanks for the advise.
I decided to drill through the bottom of the tank. Now I have a question about my returns. I want to return two Mag 12 pumps separately, with 3/4" plumbing that will enter the bottom of my tank, run up through my sand,
then disburse with a 45 degree nozzle. I would have a gate valve and a check valve on each pump, but I'm worried the check valves might fail in a power loss and 220 gallons of water could drain down, through the returns,
overflowing my 75 gallon sump.
<Me too, they will fail, not if but when.>
Should I be concerned about the check valves failing?
Is there a brand of check valves you recommend that can handle 220 gallons?
<I just would not. There is always something in a marine tank that will keep these from sealing in a pump outage. Even the slightest little leak will end in disaster should the power be off too long. I always try to place returns high up and just avoid the issue all together.>
Jon Weber
<Welcome, Scott V.>

Overflow sump noise   5/13/10
I have a 100 gallon saltwater tank set up with freshwater. I am having issues with the noise that the overflow sump/lines is making (air/water mix causing gurgling and slurping). Venting is not an option because I can't
get the top of the vent line above the tank level.
<Any overflow will need to be aspirated to function properly.>
I have tried aspirating with different sized tubes and other objects, but none have seemed to help.
Right now I have a sponge on top of the overflow line and it helps a little bit, but its still noisy. Any ideas? Another question I have is about covering the sump top so fish don't get sucked into the sump. Any ideas
as to what to cap the sump with and still allow proper flow?
<Some more information is needed here to make an assessment. What size overflow line(s), how is it plumbed, what size pump, what brand/type of overflows?>
Thank you,
Chris French
<Welcome, Scott V.>

Re: Overflow sump noise 5/19/10
I have a Walchem Iwaki magnetic drive pump.
<Hmmm, size/model?>
The overflow line is 1/2 inch PVC running into 1 1 1/4 inch flex hose which feeds the filter sump. The supply line is 3/4 inch. See attachment for plumbing.
<A 1/2" overflow drain line? This is almost useless, even in the smallest of tanks. The noise you are hearing from this is the line sucking in air as it siphons. For a 100 gallon tank you need larger, multiple drains.
See: http://www.wetwebmedia.com/BulkheadFloRateArt.htm>
Thank you
<Welcome, Scott V.>

Am I understanding right? Pb realities... X in, perhaps less than X out... trouble    4/29/10
Hello Crew-
I have been reading over your site to find some answers. Could you tell me if I am on the right track?
I have a 150 gallon tank with 2 corner overflows-yes the 1" overflows. The tag that came with the tank says 700gph, you state for 1" holes the max is 300gph.
<It indeed is.>
I am going to do the two sumps linked together and a return pump. Since they drain 300gph each? Would a 950gph pump be ok?
<Once the plumbing and head loss is accounted for you will likely be close.
Keep in mind even if the overflows can handle this pump it will leave you zero redundancy, next to no margin of safety.>
I also have a 3200gph powerhead that came with the tank. My LFS is telling me to go with a Mag-drive 1800. Would this be too powerful?
<Very much so. You will spend money on the pump and to power it just to throttle it back quite a bit.>
Could you recommend a protein skimmer for this tank?
<I would take a look at ReefDynamics, AquaC or Vertex for this.>
<Welcome, Scott V.>  

2 overflows or 1? - 03/30/10
Hello gentlemen,
<Hello Steve.>
I have one brief question:
I'm about to order a 55 gal tank/stand/canopy from Tenecor and I need to know if I should get two 6x6 corner overflows or one 18 x 5 rear overflow with two drains? I understand from your FAQ section that the drains should
be 1.5" holes and 1" returns.
<The box itself is purely your personal preference. Either combo will give you enough flow to handle the lines. You will just want to make sure there is enough room within the boxes for sufficient plumbing. For a 55 I would have a minimum of two 1.5" drains. If you are going to have over 700 gph of flow through the sump I would bump it up to three 1.5" lines to keep true redundancy.>
Thanks for the help,
Steve Jonas
San Francisco, CA
<Welcome, Scott V.>

Re: 2 overflows or 1?  4/1/10
Thanks for the info.
<A pleasure to assist.>
I put in the order today for the single box with three 1.5" drains (since I want to eventually have this be a reef tank with a high turnover). They seemed to think I was a little nutty to want all those drains but it was nice to have the confidence of your experience behind my order.
<Well, all should have overkill on overflows. You really cannot have too much capacity. Why not?>
Thanks for putting on such a great website. I've gotten a lot of great ideas about how to plumb the tank from you folks and I'm planning on running a "closed loop" circulation setup at the termination of the refugium/sump return line. You'll probably hear from me again if I get stumped.
<No problem!>
<Thank you for the kind words. Scott V.>

Overflow and drilling -- 2/12/10
Hi, and good day,
I'll try to make this short. I have a 220 Oceanic with two corner overflows. They are drilled on bottom for a 1" drain and a 3/4" return.
I am going to be drilling through the back of the tank, near the top, for 2" bulkheads. One in each overflow. The are 11" x 8". Will the internal overflows be able to keep up with the bulkheads?
<Oh yes.>
I'll have a Mag Drive 18 pushing the 80 gallon sump. Thoughts?
<Will be fine, is exactly what I would do in the situation.>
<Welcome, Scott V.> 
<<Mmm, RMF would add or drill-out one of the existing 1" overflow lines... at least one other overflow through-put of size here... likely 2"... >>

More re: Overflow and drilling  2/13/10
I must disagree here Bob. I have heard of some runs when the bottom panel was not tempered with these tanks, but from what I understand most are. I would not chance enlarging the holes.
Scott V.
<Thank you for this... How about an accessory overflow through put placed near the top back corner somewhere? To provide emergency clogged/overflow capacity? B>
re: More re: Overflow and drilling
I do believe this to be his point of the original query. To place a 2" line in each box. He was just wanting to know if the teeth of the box itself can handle the flow.
Scott V.
<What? I don't see this here... In prev. corr.? BobF>
Oh yes, perhaps we are reading this differently! All I know is Tommy's burger for lunch today!!!
"I'll try to make this short. I have a 220 Oceanic with two corner overflows. They are drilled on bottom for a 1" drain and a 3/4" return. I am going to be drilling through the back of the tank, near the top, for 2" bulkheads. One in each overflow. The are 11" x 8". Will the internal overflows be able to keep up with the bulkheads? "
<Hey! Finally made it to the SD loc.... down the road a bit in Clairemont.
Remember, there are Tommy's in Hell, but there are no napkins! B>
Re: More re: Overflow and drilling
That is why my wishes state to be cremated with napkins!
<Heeee! Considering my BMI, % body fat, I won't need much more than a lit match! B> 

Re: More re: Overflow and drilling, tempered glass bottoms   2/16/10
"crew@wetwebmedia.com writes:
I do believe this to be his point of the original query. To place a 2" line in each box. He was just wanting to know if the teeth of the box itself can handle the flow.
Scott V."
Yes, that is what I was wondering. I did contact Oceanic once about the tank stand, asking what product/color they used, as I was redoing the stand.
I provided the serial number along with pictures of the tank and stand.
They couldn't tell me. Which I thought was weird as they are the ones that built it.
<Sometimes it is a matter of what panel was grabbed at the time. Some manufacturers had/have runs of both tempered and non tempered panels.>
I contacted them later on a couple of different times, wondering if the tank was tempered or not. Never got a response. From what I heard, this is typical of Oceanic's Customer Service. Or should I say NON Customer Service.
<Scott V.>

Skimmer Trade? (And Plumbing Issues Too!) -- 02/01/10
Hi, and thanks in advance for any help you provide.
<<Hiya Pam'¦let's see if I can be of service>>
I have inherited my college freshman's reef.
<<Mmm'¦hopefully this will read better than the majority of such>>
Started with a free ('it will only cost you $40 worth of salt to get running') 55 gallon set-up with standard fluorescent lighting
<<Ha! I'm guessing you didn't inquire/think past the 'to get running' phrase'¦>>
'¦over three or four years it is now a 150 gallon set-up.
<<Ah! This is actually better for you/your livestock re the increased stability of the larger system. Also'¦I'm just a BIG/BIGGER tank kind of guy>>
(hmmm if only we had known'¦that was a really dirty trick...just kidding!)
<<Ah well, rare is the hobbyist who doesn't think about upsizing>>
We love the 'little piece of the ocean' and I don't mind the upkeep while the progeny is away at school studying biology.
<<That's a good thing as you will likely keep/have this tank for some time'¦I'm betting>>
However, I am an amateur and working hard to learn through on-the-job training...
<<Read, read, read'¦>>
Bought used, the system came with a ProClear Pro 300 used as a sump, no bioballs or anything.
<<It's not uncommon to see 'converted' wet/dry filters used as sumps on reef systems>>
The ProClear is a strange design with one end side lower (yikes! I'm sure there is a point to that, but it annoys me)
<<Indeed'¦a wet/dry filter generally runs with a quite low water level (remember, it wasn't designed as a 'sump'). I reckon the design saves on material'¦perhaps eases access'¦or maybe someone just thought it looked snazzy [grin] >>
so to avoid the possibility of an overflow in the event of a power failure I only keep about 15 gallons of water in it. The water level is about 7-8'.
<<This is about normal'¦though if there is room and it is desired'¦a larger, simple plain glass tank could be utilized to increase volume>>
Overflow water dumps into the first compartment then into a felt filter sock that is washed 2X week.
<<Kudos on the maintenance of the filter socks'¦a huge source of decaying organic matter>>
We are using an ASM skimmer (G-3 I think) with a Sedra ksp-5000 needle wheel pump in the second compartment; it is emptied/cleaned 2X week. The return pump is in the third compartment along with the float switch for the auto top-off and the return for the phosphate reactor. Oh, and there is Chaeto growing albeit very slowly in the third compartment as well.
<<The Chaetomorpha would serve better in a dedicated refugium receiving raw water from the tank, and then drained directly to the pump chamber of the sump. The slow growth is likely due to much of the organic/nitrogenous material being removed by the filter sock and skimmer before it reaches the macroalgae (assuming it is sufficiently 'illuminated' for growth to begin with). But still, this is not all bad'¦ As long as the Chaetomorpha is healthy and not decaying/falling apart, it is providing an excellent matrix for epiphytic matter, small beneficial crustaceans/planktonic organisms, et al>>
I use Bulk Reef Supply's two part product and magnesium to keep parameters at about:
dKH 9
Calcium 400
Magnesium 1280
pH 8.2
Others are:
Salinity 1.026
No detectable nitrate, phosphate or ammonia on API kit
<<All good>>
There are just a handful of fish, a yellow tang, hippo tang,
<<This tank is quite borderline for this very robust, active, and even skittish fish'¦in my opinion>>
three Chromis, a scooter blenny, and a pair of clownfish. A lot of coral, and a very mixed assortment'¦About ten smallish sps colonies, a few mushrooms, a small cauliflower sized hammer, a softball sized candy cane and two smaller ones, a huge open brain, two large Cynarina, a Sinularia and two Sarcophytons, some pulsing xenia, GSP, as well as several blastos, micros and Acans. Lots of Zoanthid colonies'¦I think that is the bulk of it.
<<Ah yes, the ubiquitous 'reef garden' for sure. If not already, I would run a cup or two of carbon on this system, or perhaps some cut-up Poly-Filter (not to be confused with polyester filter material) as a hedge against this noxious mix of organisms>>
2-250W metal halides and two actinic VHOs. I have no idea how much rock, it was bought a little at a time'¦it probably takes up about ¼ of the volume of the tank'¦just a guess. Everyone seems to be happy and healthy and growing.
Too much information? LOL
<<Not at all>>
My question is this, and I feel crazy considering it'¦ My friend is getting rid of a 240 gal set-up. She has been using an AquaEuro USA downdraft skimmer with a RIO 2500 pump. It seems quieter than the ASM
<<Really? I wouldn't expect this (I generally find downdraft skimmers to be noisier and requiring more powerful and 'energy hungry' pumps than needle-wheel skimmers)'¦I wonder if the skimmer is 'underpowered' with the RIO pump'¦ And as a note'¦the RIO pump is not a good performer for the long term>>
and she's willing to trade the ASM for it before her system goes to a new home. My husband and I would love to reduce the noise a little, however, since everything seems to be rocking along pretty well, I wonder if I am nuts thinking about trying something new. To add to my worries, I can't find a lot of info about the AquaEuro downdraft pro or con. What do you think?
Given the option, would you trade skimmers?
<<I would not'¦but then I am extremely fond of the needle-wheel style of skimmer (I have a Euro-Reef CS12-3 on my own reef system). While the GSM skimmers don't necessarily utilize the best of materials in some instances in my opinion (polycarbonate vs. acrylic), I would still favor it over the 'unknown' downdraft skimmer here. As for the noise re the GSM'¦ If it is more than a couple years old, replacing the pump and/or impeller may help, as the Sedras do 'wear' quite readily in my experience>>
On a side note, a lot of the noise seems to stem from the overflow water as it rushes into the sump
<<Oh'¦very common>>
'¦any suggestions there?
From the overflows the water travels down flexible ribbed tubing that looks like something from a swimming pool.
<<Hmm'¦replacing this with 'smooth' rigid PVC pipe can help re the induced turbulence>>
Each dumps into T's that have about 7-8' of perforated pvc pointing down into the sump and about a 3-4' length of capped off PVC pointing upward. (if they aren't capped, it burbles water out the top.) I don't know what that is all about; it is the way it came.
<<Likely to alleviate the turbulence/noise (and associated bubbles) you mention. Perhaps an attempt to 'aspirate' the drain line, though this is better done 'at the top' where the drain exits the tank (do search WWM re). You could remove the 'tees' to reduce resistance/splash-back, and replace these with an 'ell' fitting to divert bubbles from going 'back up' the line, and positioned below the water line to further 'mute' noise. But if all this seems too daunting to take on'¦simply reducing the volume of water pumped to the tank will result in a reduction in noise from the overflow(s). If you can tell me the specific number and diameter of your overflows/drain lines'¦and the type/capacity of your return pump'¦I can then better determine if this is a viable route to take. It is very possible that you are merely pumping more water to the tank than the drains can quietly (and maybe even safely) handle. It is very likely that a flow of just a few hundred gph would suffice'¦and if you have a 1' drain trying to handle more than that, well'¦>>
Plumbing is not our strong point'¦my husband is an electrician :)
<<So the lighting is no problem, eh [grin]'¦>>
Could some noise be reduced there with some modification?
<<No doubt'¦but I need more/more detailed info on your pump and plumbing system>>
Thanks again!
<<Happy to share'¦be chatting! Eric Russell>>
Re: Skimmer Trade? (And Plumbing Issues Too!) -- 02/02/10
Thanks Eric,
<<Quite welcome, Pam>>
Ha ha'¦ After previous encounters with a steady parade of reptiles, amphibians, mammals I fully knew that no "free" pet only costs $40 LOL!
<<Indeed'¦ And though I don't think it is the case here'¦oftentimes the 'cost to that free pet' is much more (worse)>>
We know we'll end up with the 150-no problem,
<<Ah good>>
but of course it has involved a lot of education for me.
<<And some measure of enjoyment as well, I hope>>
I really appreciate your role in that. :)
<<Is my pleasure>>
Back to the matter at hand. There are two overflows in the tank each fitted with a dursa.
<<Durso'¦as in Durso Standpipe'¦a very helpful device for improving the performance and increasing the 'silence' of the drain lines>>
I believe the outlets are 1" diameter.
<<Very likely so as this is (unfortunately) a very oft used diameter on production tanks. This being the case, you maximum flow capacity is about 600gph'¦and maybe less depending on the design of the system>>
The return pump is a Mag-12 1200 GPH.
<<Hmm'¦even with head loss I imagine the output is still a bit too much for your drains'¦creating a dangerous and 'noisy' surge/siphon effect. I suggest you install a gate-valve (not a difficult to adjust ball-valve) on the output side of the pump and temper the flow to see if this eases the noise from the drains>>
When you say the ells should be "positioned below the water line", they already are, the water level in the sump is above where they are plumbed in through the wall of the sump (if that makes sense) and of course they also discharge under the water level as the current pvc is about 7-8 inches long.
<<Ah, okay'¦then the 'tees' you mention are attached to this and positioned on a vertical plane? If it's possible, try twisting the tees to a horizontal plane (uncap the plugged end as well). Though this will probably be unnecessary if you reduce the flow from that Mag-12 pump>>
My question with reducing the size of the return pump would be with regard to flow and water turnover, etc.
We currently have the return water coming through LocLine that is positioned to emphasize the flow as well as two middle sized Hydor powerheads. Not sure what size but not the smallest and not the largest...how's that for being technical?
<<Hee-hee! Don't forget to adjust that thingy bob on the watchamacallit, too>>
That is it as far as flow or circulation is concerned. If we used a smaller return, do you think we would need to add another powerhead?
<<Maybe not, it depends on how the different organisms you have are positioned/placed in the tank and how the flow is adjusted re, and of course how much there is'¦but it most likely wouldn't hurt. I've seen very, very few instances where a system wouldn't benefit from more water flow>>
Any other questions?
<<Not from me'¦you?>>
Oh, and thanks for the opinion on the skimmer.
<<No problem'¦have lots of 'em [grin]>>
<<Cheers'¦ EricR>>

Circulation/Flow'¦Adding Additional Overflow -- 01/12/10
First of all: your website is incredibly helpful and I have learned so much from you guys.
<<We are happy to have been of service>>
If only I had discovered it earlier, I could have prevented the situation I'm now facing!
I have a 125 gallon tank that was supposedly "reef ready" with a pre-drilled 1" overflow drain in the bottom of the tank.
<<Mmm'¦ Can be made to work with supplemental flow from other avenues/devices>>
I recently added a much larger (30 gallon) sump/refugium and plan to upgrade my existing Mag 5 return pump to an Iwaki MD40.
<<A good pump'¦and do note the difference in output and output pressure between the two models re (RLT vs. RLXT) when making your purchase. And'¦ Even with the addition of more drains to handle the extra flow, be sure to add a gate-valve to the output side of the pump to temper flow if needed>>
In terms of flow, I also have three Koralia 3s and a WavySea (currently connected to the Mag 5, but will be connected to the Iwaki once I get it); am thinking of also adding a Vortech MP40W for additional flow.
Anyway, in reading all the FAQs and articles, I understand that my single, 1" overflow, well, sucks, and I should have something much larger, and maybe even an additional overflow for redundancy.
<<Indeed'¦ The 1' overflow limits you to a 'safe' drain rate of about 300gph'¦not near enough for the Iwaki pump you plan for>>
I don't want to drain the whole tank; would be a nightmare to remove the hundreds of pounds of live rock (connected via ties, epoxy), then removing the sand, fish, etc. etc.
It seems like the best alternative is to drill an additional overflow (I'm thinking 1 1/2 inch) in the side/back of the tank a few inches from the top, and incorporate a "mini" overflow with some notched PVC (I stole the "mini" overflow idea from EricR after reading several of his responses).
<<Ah! I am pleased to know others have found the discussions to be of interest/use>>
That way, I would only need to drain until the waterline was below the point of drilling, correct?
The one issue I see is all the tiny bits of acrylic ending up in my tank from the drilling, but I could probably think of a way to collect those.
<<It's not really a concern'¦but you could use a fine net to remove the particles before they disperse, if desired>>
Any suggestions/concerns with this approach
<<It worked well for me>>
or can you think of a better way to solve this problem -- short of draining all the water?
<<At the least, adding another drain will create some redundancy/measure of safety'¦and if you go forward with the pump upgrade, it will certainly be a requirement. With proper thought to flow rate and bulkhead size (minimum 1.5')'¦what you have planned should work fine>>
Thanks again -- you guys really are the best!
<<Happy to share, mate'¦ Let me know if you need any further explanation/help with the placement/installation of the bulkhead(s). EricR>>

Re: Circulation/Flow...Adding Additional Overflow - 01/12/10
Thanks so much! I really appreciate your time and expertise.
<<It is my pleasure to help my friend... Eric Russell>>

Overflow Pipe diameter question   12/31/09
Hey guys, First I wanted to say thanks for the great write up on overflow art!
<Dang! I kept hoping ScottV, the author would see, respond>
I have designed my plumbing from your flow rate page, but had a quick question.
First, my tank is a 75 gallon with a 50 sump and a 20 fuge. My return pump is giving me about 700 GPH at head pressure. From this data, it appears that I would want a 1.5" diameter pipe.
<Yes... even two>
I have designed my plumbing based on that, but I'm getting feedback on the forums that the 1.5" drain line is not what I want, and I should go with a 1" (which seems to small based on your data.)
<Definitely too small...>
<... try it and see. If something we're important (like your health), would  you listen to "feedback?"... or people who know what they're doing?>
is telling me that I should be just fine with a 1" drain line, and that with a 1.5" drain line running out of a 6" by 9" overflow box, that there might be too much air in the system, and that could cause my overflow box to not drain properly and to back up and overflow (due to the large volume of air in the system.) Do you think this is a concern?
<... No. I KNOW it wouldn't. Wow, that's big!>
It would be bad to have my tank overflow out of the overflow box. I've bought my pipes and fittings from Lowe's (which I could return if needed.) I bought a 1.5" bulkhead from marine depot, but I could discount the cost and stay on a 1" pipe if I am going to have issues with the system not draining properly.
<The larger and more numerous the overflow/s the better>
The overflow box came with a hole size for a standard 1" bulkhead, and I was going to drill it out to make it bigger for a 1.5" (but I have not done this yet.)
Any info from you guys on this would be awesome, as I'm now getting a lot of conflicting information on using 1" vs. 1.5" and the fact that my overflow box might not be large enough to efficiently run a 1.5" drain line without overflowing issues.
Thanks a lot!
<Keep reading, learning... Bob Fenner>

Re Overflow Pipe diameter question <<ScottV chiming in>>   12/31/09
Hey guys, First I wanted to say thanks for the great write up on overflow art!
<Dang! I kept hoping ScottV, the author would see, respond>
<<Scott here, missed this, sick dog yet but again....this danged flu is kicking my butt!>>
I have designed my plumbing from your flow rate page, but had a quick question.
First, my tank is a 75 gallon with a 50 sump and a 20 fuge. My return pump is giving me about 700 GPH at head pressure. From this data, it appears that I would want a 1.5" diameter pipe.
<Yes... even two>
<<Fo sho.>>
I have designed my
plumbing based on that, but I'm getting feedback on the forums that the 1.5" drain line is not what I want, and I should go with a 1" (which seems to small based on your data.)
<Definitely too small...>
<<Way too many people in the forums nowadays are advocating for using siphons in overflow lines. A 1" can flow 1200 gph in this case, but it is just not reliable, nor wise. It WILL fail in time.>>
<... try it and see. If something we're important (like your health), would you listen to "feedback?"... or people who know what they're doing?>
is telling me that I should be just fine with a 1" drain line, and that with a 1.5" drain line running out of a 6" by 9" overflow box, that there might be too much air in the system, and that could cause my overflow box to not drain properly and to back up and overflow (due to the large volume of air in the system.) Do you think this is a concern?
<... No. I KNOW it wouldn't. Wow, that's big!>
It would be bad to have my tank overflow out of the overflow box.
<<It would, the reason for the need for a larger, ideally multiple, line.>>
I've bought my pipes and fittings from Lowe's (which I
could return if needed.) I bought a 1.5" bulkhead from marine depot, but I could discount the cost and stay on a 1" pipe if I am going to have issues with the system not draining properly.
<The larger and more numerous the overflow/s the better>
The overflow box came with a hole size for a standard 1" bulkhead, and I was going to drill it out to make it bigger for a 1.5" (but I have not done this yet.)
<<I surely would, and drill another while you are at it.>>
Any info from you guys on this would be awesome, as I'm now getting a lot of conflicting information on using 1" vs. 1.5" and the fact that my overflow box might not be large enough to efficiently run a 1.5" drain line without overflowing issues.
Thanks a lot!
<Keep reading, learning... Bob Fenner>
<<I know there is quite a lot of "info" out there re overflow rates. I urge you to ask any that give you advice how they have measured the results. Many in forums just speak from experience claimed by others, some just make stuff up! I can tell you I have personally spent many hours, days, even into weeks of my life setting up, testing and actually quantifying (hence the article you looked at) these numbers. They are real, those that run more (not think they do, but actually do) should invest in several mops, maybe a large shopvac.>>

Where to Drill Holes for an Overflow? -- 12/04/09
Thanks for maintaining this great site.
<<Welcome'¦is quite the collaborative effort>>
I tried searching for my answer for a couple hours here, but there is just too much information to sort out. I have learned quite a bit about other things not related to my search however.
<<Very good>>
I have a non-drilled 75g acrylic tank 48x24x15. The tank has been up and running for a couple months without a sump, but now I think I want to add one.
<<A very useful adjunct>>
I was about to add a siphon-type overflow box but after reading through your site I have definitely decided against it.
<<Some mixed opinions for sure, with most I think considering exclusion of such the better option. But with some thought to redundant systems they can be utilized quite well'¦though my personal preference far and above is the 'drilled' gravity-drain type overflow>>
My next option would be to drain some of the water from the tank and drill a hole in the back and make some sort of overflow drain with a 90-degree elbow and some PVC.
<<This is a very doable design. I have similar throughputs/drains on my own reef display tank>>
Is this a good idea?
<<If done with care and good thought to the design/installation'¦yes it is>>
If so, where should I drill the hole?
<<On one of the non-viewable panels at least an inch in from the edge of the panel (this measurement is for 'Acrylic' tanks'¦I would allow more distance on a 'Glass' tank, for strength)>>
How far down?
<<This will depend on how you plan to handle the 'internal' component of the drain. If you simply plan to drill and install a bulkhead and screen (FYI -- the bulkhead screen will greatly diminish the flow capacity of the drain) then you will want to place the bulkhead very near the top of the tank by drilling the hole for the bulkhead with the upper edge about an inch from the top edge of the panel. This will give you a non adjustable water height in the tank of somewhere around the centerline of the bulkhead'¦dependant on the flow rate of the sump return pump. But might I suggest as a better alternative, to utilize a 90-degree ELL fitting on the inside of the drain bulkhead. Doing such gives you a means to 'vary' the water height in the tank by rotating the fitting to one side or the other, and you can even cut notches/teeth in to the fitting allowing you to place its upper rim closer to the top of the tank and providing a bit more 'security' re flushing small fishes to the sump (though I have found this risk to be very small). Such a setup also gives your drain much more flow capacity over the plain bulkhead w/screen>>
What size?
<<If installing only a single drain then go 2' if possible, though a 1.5' drain should also serve'¦with a 'pair' of the latter being your best option here in my opinion>>
Should I also drill a hole for the return while I'm at it or can I just pipe it in from the top?
<<You can go either way, your choice'¦though the former does 'look' better and won't be 'in the way' of a light hood/canopy if being used>>
Does the return hole need to be smaller?
<<For the size of your tank and the pump likely to be utilized, a 1' return will serve well>>
I obviously have no experience with setting up a sump.
<<Do peruse our site re'¦start here and follow/read among the associated links in blue (http://www.wetwebmedia.com/sumpdesfaq.htm)>>
If this is all a bad idea, what would you recommend?
<<I think this is a fine idea, with the right approach. I also want to mention'¦. When drilling the hole/s for the bulkhead fitting/s, be sure to use a properly sized 'Bi-Metal' hole-saw (be sure to research the proper hole-size for the bulkheads used) available at any hardware or home store. Also when drilling, take things slow and be sure to back the hole-saw out of the cut often. Acrylic is not difficult to cut/drill, but the heat build-up from the friction of the saw will start the Acrylic to melting'¦if you're going too fast and you stop for even a few moments, you can 'lock' the hole-saw in the cut and may have real trouble getting it free again>>
Thanks again for your wealth of knowledge!
<<Happy to share'¦ EricR>>

Standpipe Question (AGA or Durso) -- 10/26/09
Dear WWM.
<<Hello Dan>>
I just ordered a 210g AGA with built in overflows. The tank is drilled for 1-inch drains and ¾ inch returns.
<<Mmm, yes'¦and unfortunate'¦larger drains could/would make a world of difference>>
I have two options for standpipes. Option One: use the standpipe drain kit that AGA sells, or option two: use the standpipe from Durso's web site that uses a 1 1/4 inch thin-walled PVC with a reducer bushing to fit the 1 inch bulkhead. My question is, would there a difference in flow rate and noise when using either of these.
<<Indeed'¦ The Durso was developed for just such as this and would be my choice here'¦though you should still plan for no more than about 350gph of gravity flow for each 1' drain>>
Thanks in advance for all the help,
<<Happy to share'¦ EricR>>

Re: Standpipe Question (AGA or Durso) -- 10/27/09
It appears that the AGA kits are styled after the Durso design; is it still better to go with the Durso standpipe?
<<In my opinion'¦yes. But if already in hand, try the AGA first and see if it meets your requirements. EricR>>

R2: Standpipe Question (AGA or Durso) -- 10/28/09
Thanks for the help.
<<You're quite welcome... EricR>>

Sump And Skimmer Problem 6/30/09
Hello and thank you for taking time to address my questions.
<Hello Roxanne>
I have several questions:
1) I purchased a used aquarium set up. It is a 90 gal corner aquarium that is drilled for a sump. This is my first sump set up but I have been in the hobby for 10 plus years. My problem is that the sump drains faster than it fills. Now I am sure I am missing something obvious here, but for the life of my I can't get it to work properly. I have searched your site and found an article that seemed related, it talked about sump noise and that I should remove the bulb float valve. I did and had no reduction in noise (it got worse) and no impact on water movement. The drain hose is 1" and the return is ¾ .
<Typical, but are we talking about noise now or the sump problem?>
I am using a Rio3100 pump. It takes several hours for the chamber that houses the pump to drop significantly.
<How long is your return line? I'm guessing that the Rio is pumping water out to the tank slightly faster than the drain hose can supply. A one inch drain line is typically good for about 550gph provided no restrictions, bends/elbows, and gate/ball valves are used.
The chart below will give you an idea of what your pump will put out at a given head height. Again, this
is with no restrictions in the return line to the tank.
0" 1` 2` 3` 4` 6` (head height)
900 870 782 700 690 500 (gph)
As far as the gurgling/sump noise, using a Durso Stand Pipe generally takes care of this problem.
See here. http://www.dursostandpipes.com/>
2) My second question is, I need a new skimmer. Ideally I would like it to go under the tank either on or in the sump.
<You will sleep better at night if it's in the sump.>
My issue is that the initial chamber of my sump has a lid on it. The sump is acrylic and has 4 chambers. The initial chamber has a cover that allows for the drain hose to go right thru the lid, but this of course will impede my ability to put a skimmer in that chamber. I read your articles recommending raw water for
the sump, but I can't see a way to attach a sump <you do mean skimmer, correct?>
into this chamber, what is my next best alternative?
<Why not remove the lid if otherwise there is room for a skimmer.>
What skimmer would you recommend for this application?
<I would need to know how much room you have in the sump for a skimmer first, providing you're willing to remove the lid.>
3) Lastly, do I need a light in my sump? What are the advantages & disadvantages to keeping this area in the dark?
<Lighting is only used if the sump is configured as a refugium. Otherwise, no need to light.>
Thanks again for all your work on this site, it has become a site that I visit daily!!
<You're welcome. Sending a couple of pics along of your sump and overflow from the tank will help much here. James (Salty Dog)>

Here we go again.
Re: sump & skimmer problem..... 6/30/09

<How long is your return line? I'm guessing that the Rio is pumping water out to the tank slightly faster than the drain hose can supply. A one inch drain line is typically good for about 550gph provided no restrictions, bends/elbows, and gate/ball valves are used.
<<Hmmm, no, 300 gph max. safely, reliably and without noise. Please read http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm
James, we have been over this time and time again. Please do take the time to actually measure this, you will be amazed!>>
As far as the gurgling/sump noise, using a Durso Stand Pipe generally takes care of this problem.
<<Not if the overflow capacity is being exceeded. Scott V.>>
See here. http://www.dursostandpipes.com/>
And for the actual quantified tests do see:
y-2009/aquarium-bulkhead.aspx too! Scott V.
Sorry about that, too accustomed to seeing false advertising on flow rates of overflows, etc.
I do appreciate the link, just the chart I've been looking for.
Hi Scott,
<Do you have any useful plumbing links you would like to share?
James (Salty)>
Re: Plumbing
I love the email format! Yes, I do: http://www.fishchannel.com/fish-magazines/freshwater-and-marine-aquarium/jul
, though it does look like you have seen it by now! Do realize these are the "best scenario" flows, hence the 300 per recommendation.
Scott V.

How to kick start the new setup? Bio. filt., & through-put/hole options  6/11/09
Hello there - This is Sunny from NJ
<Hello, Sunny CA here.>
I am setting my first marine tank (have kept FW Cichlids for 4 years now).
After about 3 months of reading (This is a great site and lots of wealth !!) here is what I narrowed down to for equipment.
<Ah, good first step, research!>
150 Gallon RR TANK.
<Do have a good look here first:
These "reef ready" tanks generally use 1" bulkheads and are hard to consider truly RR!>
Pro clear 400 refugium/sump (42X16X16)
ASM G4 plus skimmer.
External Pump - Blueline BlueLine 70 HD rated at 1750 GPH
I will start with FOWLR and then add coral slowly.
Everything goes under the tank.
What I am confused about is how to start this setup initially. I mean, should I load the refugium with MUD ( 5 - 6 inches I guess?) and put the micro algae (Chaeto) in the fuge and then fill water and cycle everything with live rock?
<The Chaeto is not particularly delicate, but I would not add it until the rock is cured.>
I am not using bio balls. I plan to start with 75lb rock in tank and 25lb in fuge. Can I cycle everything together?
<You can, desirable IMO.>
I was planning to use BIO Spira (have used in FW with great success) for speeding cycling. If I use BIO Spira will that harm the micro alga in fuge?
<No, but it is completely unnecessary with the addition of the live rock.>
How do I start placing rocks in tank? I have read different things about this. Should live rock go on bare bottom of the tank and live sand around it or should I lay down live sand and then add rock on top of it?
<Either can work, but if you are going to have a deep sand bed it is good to support it some how, critters can and will dig causing the rock to shift and tumble. In this case you will want to place some of the rock in contact with the bottom. Some even just build little PVC feet to hold the rock.>
How deep should the sand be? I have read about gas pockets in sand if too deep?
<1" or less or 3" or more. DSBs get a bad rap, don't be afraid of them.
See: http://www.wetwebmedia.com/deepsandbeds.htm and the linked files above.>
I will upload the plumbing design in my next post.
Sorry for the long email, but I don't want to screw this up :-)
<No problem, better to do it right the first time!>
Love the site and love the fishes ....
<Thank you, Scott V.>

Re: How to kick start the new setup? 6/12/09
I actually got the tank already. AGA 150 gallon drilled tank with 2 overflows. What are my options now?
<Well this is likely 1" overflow drains, so your first option is 600 gph total or less, but this leaves no
redundancy. The other option is 300 gph or less, which would leave redundancy. Another option is to
drill for larger throughputs within the box, on the back wall. See:
http://reefercentral.com/Videos.html Scott V.>

Re: How to kick start the new setup? 6/13/09
Thanks for all the insight.
Here is where I am confused now about the GPH. I am not thinking of getting bigger holes drilled. I have read that to keep FOWLR and some mixed corals the flow should be 10X - 15X and for SPS should be 20X - 30X.
<Fair estimates.>
That said, I only have 600GPH on my 150 gallon tank. I will also use a pair Koralia PowerHeads (model 6) each one is rated 2200 GPH. If I do this, can I say that my total GPH is 2200+2200+600 or somewhere
close? Or am I completely wrong in calculating the 10X and 20X flow rate?
<Nope, you are on the right track here.>
I know a lot of people use AGA drilled tanks with 1 inch inlets and have kept SPS corals with success.
<Oh yes, just be vigilant. With these bulkheads at full capacity the smallest of obstructions (snails, algae, etc.) can lead to overflow blockages and water on the floor. It can be done no problem, but that is the issue.>
Thanks again for the help and time.
<Welcome, Scott V.>

Re: 1" Overflow Woes 6/4/09
Scott, Sarah..someone in the crew? Hard to know who's gonna answer next hehe...
<We will see whom, lets pause and see!>
<Wait, hold on.>
How much flow will go through a sideways positioned 1" bulkhead, is it still 800gph maximum..700gph? cant remember exactly the flow number.
<As an overflow drain? Nowhere near.>
Usually they are vertically positioned like on the bottom of an overflow box. I am using a used 60 gallon acrylic tank I had sitting around as a refugium for my larger 240 gallon setup. I wanted to input water from a Rio pump depending on the maximum drain flow I can get from a 1" bulkhead positioned on a short side of the 48"x15" tank located close to the top of the tank. The bulkhead would act as an overflow outlet rather than utilizing any overflow box? Can that work with a small inflow of water. I can't use a 1.5 in bulkhead because of height/conjoining with main sump restrictions/issues. It's a refugium and I figure plants/algae of any kind like to have reduced flow. A slow flowing nitrate absorbing refugium...
Thanks for the advice,
<Welcome, see: http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm All the tested answers are here. Scott V....or am I?>

Re: 1" Overflow Woes 6/5/09
That link you sent me does not really explain horizontal flow rates for a 1" bulkhead.
<It will be less, by a 20% margin at least...does depend on the length of the run.>
In any case, how would you establish flow for a refugium using a 60 gallon acrylic tank? Keep in mind it is raised 5 or 6 inches from the ground because i was planning on have water come out a 1" bulkhead as sort of an overflow, maybe 2 1" bulkheads will work?
<At the least, I would do whatever possible to use 1.5" here, for any overflow.>
How would you go about installing this?
<Big holes, more than one ideally.>
<Scott V.>

Pump sizing? Inadequate number, diameter of overflows, too small transit volume sump, U.S. fails in attempt to boss another nation... no new news at 11:00   5/10/09
Good morning,
You guys and gals provide a wealth of info to us all and I am sure everyone is as great full as I am that you provide the services that you do (for free no less!!). I have been contemplating the return pump choice for months now and am looking for a little more guidance if you will. I have read all through the plumbing and pump selection sections and am still not sure which way to go. The tank I have is a 90 gallon acrylic with a 30 gallon sump currently empty. My debate is this...when the tank was previously set up the water drained to the sump through a 1" bulkhead into a 10 gallon sump
<Both inadequate... should have larger and two drains... and a larger transit volume (sump)>
then pumped back to the main tank with one Rio 2600 LPH pump through 3/4" flex tubing to an over the top U fitting that then Y'd out to two 1/2" loc-line nozzles for the left side. The right side was exactly the same except the pump was an off brand 2792 LPH and the flow rate from each side was a little disappointing although it worked. Now I have decided to change it up to only using a single pump that will feed two 3/4" x 3 1/2" loc-line nozzles. I have all ready drilled and installed a 1" bulkhead in the back of the overflow box that connects to a "T" fitting with reducers on the output side to 3/4" that are also drilled through the box and have the 3/4" loc-line all ready connected up. In order to get down to the pump I have a 1" 90 (all the rest of the plumbing is 1")
<Mmm, I would have used this "hole" through-put for the return and drilled two outlets sufficient to fit two 1 1/2" bulkheads for the two drain lines... At this point, I'd likely re-drill the 1" out to one and a half inch accommodation (get the bulkheads first and measure) and add another at the same "height" on the back of the tank, distal to the first one>
that goes down to a 45 that will go though the stand to another 45 to a check valve (all though not sure about this valve yet) to a true union then reduces to a 3/4 female adapter for the pump. Judging by the poor flow from the last setup I don't want to have the same issues and spend money on different pumps for no reason.
<Understood and agreed... And you're going to be in trouble immediately with the current inadequate 1" overflow... and ultimately when (not if) the one becomes occluded some bit/how>
The tank will be primarily LPS but I know how things go hence the reason for a 1" return "in case" higher flow will be needed for SPS. I have been trying to decide between using a MAG 9.5 or the 12, or something completely different?
<See WWM re pump selection for circulation... but you will need to change the plumbing in any case>
Leaning towards the 12 cause of the number of restrictions but unsure if that's even enough.
<Another alternative is to go with some internal pumps (see WWM re... Koralias, Vortechs...) and have less flow to/through your sump... again... having more flow here with the new plumbing configuration and pump will NOT work. The 1" drain by itself won't "keep up" and the 10 gallon tank will be under, then over-whelmed when the pump is going full out and shuts off for whatever reason>
There will also be 2 Koralia 3's for movement behind the rocks pointed up-ward, and two controllable Koralia 3's at opposite corners intersecting the flow from the return pointed downward.
<Oh! Well then... for flow's sake alone, I would not switch pumps period>
Sorry for the Lengthy e-mail but wanted to give you as much info as I
could. Any thoughts, suggestions will be much appreciated.
Thanks in advance,
<Mmm, please read ScottF's treatment re one inch drains here:
and the linked files above. Bob Fenner>

Re: Pump sizing   5/11/09
Thanks for your swift reply and suggestions. I think I may have confused you a little as i re-read my initial query it confused me a little as well.
The 10 gallon sump and 1" drain was from when it was previously setup it now has a 30 gallon sump and a 1 1/2" drain coming from the overflow box.
The 1" that I drilled in the back of the overflow box is for the return.
The debate about the pump size is that I know the force of flow will be increased at the output since it reduces from 1" to 3/4" I am just worried about it being only a trickle. I attached a VERY ROUGH sketch to try and clear things up a bit.
Thanks again,
<I do think this will work out much better. Though I like having redundancy in overflows, the diameter of these lines will likely be suitable. BobF>

Re: Pump sizing (Bob)  5/16/09
Hello again,
Ok so now that we are both a little less confused, should I still stay with one of the old pumps that push a little over 600GPH or should I upgrade to a MAG 9.5 or even a 12 so that it is not a trickle coming out of the outlets?
<I would still keep the flow to just a few hundred gph through the overflow. Even with a 1.5" drain offering up to 750 gph or so max it is a good idea to leave some extra capacity should the thing become occluded.>
Thanks again
<Welcome, Scott V.> 

R2: Plumbing a 95 Gal FOWLR -- 05/09/09
<<Hiya Dave>>
I think I understand the over the top closed-loop manifold,
<<Ah, good>>
but another issue has surfaced during my reading.
The tank manufacturer (Glasscages.com) is telling me that the 95 gal. tank (36"x24"x24") can not structurally support 2 overflows with that each have a 2" drain and 1.5" returns.
<<I see'¦ And likely best to heed the manufacturer's warnings re>>
Therefore, they recommended one larger overflow in the back center of the tank that houses a 1" return between two 2" drains. Will this configuration work based on what we spoke about below regarding turnover, etc.?
<<Sure'¦ Especially if you go with the 'true' closed-loop manifold return over the top of the tank. In fact'¦ You could go with a single 2' drain to service the sump (honestly, you could even go with 1 ½' here and use a smaller sump return pump), and size the other drain to the size of the intake of the pump you will use for the closed-loop. (i.e. -- if the pump has a 1' intake, then utilize a 1' drain/bulkhead to feed it)>>
I will get back to you with my overall plumbing design incorporating your comments below once I get the tank items squared away. Regards, Dave
<<Sounds good'¦and do let me know to if we need to chat more re these drains and returns. Cheers, Eric Russell>>

1" Overflow Woes 4/30/09
Hi again Scott,
I don't mean to ask a million questions everyday. But I did a 55 gallon reef for someone, still in the finishing works....
I ran into a problem with the 1" drain line.
I am having large bubbles and gurgles coming out of a 1" kink free black flex tubing that leads right into a filter sock. The tubing comes out from a 1" slip x 1" hose barb fitting from a 90 elbow from a 1" slip bulkhead.
<An all too common story with the 1" lines.>
The return pump is a Rio 3100, <Too much for a 1" drain.> within the overflow is the 1" drain bulkhead with a Durso pipe on top of it, small hole on cap is large enough for adequate air flow.....I tried bending the drain tube in several directions to see if angling would reduce gargles and shooting bubbles, nothing positive happened.
<Nothing will.>
Also tried removing cap on Durso to see if anything happened....nothing...
I thiiiink the tube may be too small to handle the water flow and would force air down it faster...
I am considering using the specific 3ft segment of drain tubing from Advance Aqua Tanks, the larger diameter of the drain tube may possibly reduce this problem, also considering downsizing return flow to a Rio 2500.
<The larger tubing will make no difference. The 2500 is still too large, more in the neighborhood of a 1400. Even then there is no redundancy in the overflow.>
Would these two fixes solve my problem here?
<No, see re the 1" line and redundancy:
Thanks for your advice on this one.
<Welcome, Scott V.>

Re: 1" Overflow Woes 5/11/09
Hey Scott V.,
<Hey there Matt, sorry for the slow response, I have been out of net for a while.>
I fixed the problem. I used 1" drain specific tubing and removed the 90 elbow. There was too much restriction with the 1" barb x slip fitting as opposed to using the full 1" pvc diameter i now have on there. It doesn't make any sloshing or bubble noises anymore. It flows from the Durso straight down through bulkhead into the tubing which curves right into filter sock. No problems. Didn't need to downsize pump after all...
<All sounds good, just realize the difference is minimal, you will still be near the limit of what the overflow can handle. The slightest restriction, i.e., snail, calcareous buildup, etc. can lead to water on the floor!>

Finishing touches on refugiums, pipefish, and holes oh my...3/7/09 Hello Bob, Scott, Eric, or whomever is there... <Scott V. with you this go round.> After probably reading this 100 times a day, I must also say you guys/gals are great!!!? <Happy the site has helped you!> A job well done and don't pay one bit of attention to my wife being jealous or disliking you...;]!? <Uh oh.> I can only begin to guess the time given by the whole crew for newbies like us!!!? After many countless hours of studying WWM am going to make my first purchase in two weeks....MY TANK...Yaaayy!!!? <Congrats.> I would like to ask a few specific questions if I may, so I can take the leap!? First off, Im purchasing a custom 72/75 gallon tank, I was going to have {2} 3" holes drilled for 2" bulkheads and a single 2 3/8" hole for a 1.5" bulkhead. The guy building the tank for me said that those sizes were for sch 40 and that they were junk. Instead he said I would need for them to be sch 80 or they would end up cracking or wearing out. Said every customer who had em...had problems. <There is no need for schedule 80 in aquarium applications, the pressures involved come nowhere near warranting this. I personally have thousands of customers out there using sch 40 with no issues...the fact that he has makes me wonder what is being done wrong.> He also said instead of 3/8" glass I need 1/4" for the size holes im having drilled. Do you feel I need the sch 80 bulkheads?? <Nope.> Would you agree with him on the glass as well?? <If I am reading this correctly, to go thinner? No, 3/8 minimum for this tank.> Reason I ask is im sure with those upgrades there's an extra buck in there somewhere for him. <Possibly.> I was thinking all the holes on back wall, the 2 inch bhs near the top by the corners and the 1.5 inch bh near the center at top. Would it be better to have these clustered together rather than spread apart like that?? <No real difference, put them where you want them.> The 1.5 will be for the closed loop, is it ok to be at the same level as the 2"s?? <I would place it lower to keep it from drawing in air/air bubbles near the top.> Speaking of closed loop...hehe...will my outputs {swiveling els/LocLine} need to be the same length to provide even circulation?? <Nope.> I'd planned on one or two being longer to reach middle tank level. <Will be fine.> Sorry for being so sporadic, I feel im so close to actually putting my plan in gear that I've gotten a little nervous...; [ ! I'm wondering how noisy 750-1000 gph will be coming through a 40-55 gallon sump?? Can you weigh in?? <This can easily be managed. You may have to play around with the baffling a bit, see: http://www.wetwebmedia.com/ca/volume_3/cav3i1/Baffles/bafflesart.htm, this technique works great.> When I hear about not maximizing flow capacity to save on noise etc, does that mean just having a smaller pump than what the overflow holes can actually handle?? <Part of it, ideally you will flow the overflows at 1/2 or less than what they can handle, this way you will have a backup should one fail.> Ok last two ?s... I'll be using flex pipe for my plumbing, I will need to put a valve on line going to the refugium to control flow. <OK, but if (just incase) you are drawing this off of an overflow line you will want to have a T before the valve leads to the refugium. This way when you choke the valve a bit the overflow line has a bleed off, still has its full flow capacity.> For that and connections to bulkheads and pumps, will I need to form some kind of hard pvc union for the flex to clamp on?? Does that make sense?? <Hmm, yes, plastic hose barbs. If you wish to use flexible material to plumb do also consider the flexible PVC, sold as SpaFlex in many hardware stores. This piping is forgiving, flexes, and can be solvent welded into PVC fittings just like regular PVC. You do need a PVC solvent rated for flexible PVC, but if you read the fine print on many solvents out there they are actually rated for flex.> Ok last one! For the refugium, I'll have to make it a display refugium or the wife will go crazy {she doesn't have the slightest interest in my "obsession"} so I plan on having a 55 gallon set up beside and below the display. I will going for a DSB for NNR, and LR with Chaeto for a good pod population. It would be awesome for a pipefish/seahorse or two to reside in there!? Given the refugium setup would that be ok for syngnathids?? <It could work, sure.> Also do you feel they will demolish the whole pod population?? <This is the concern with adding these, ideally a refugium provides the pods a place to grow without impediments like being eaten!> Whew. For some reason I feel a lot better now...hehe. By the way, can anyone tell me how I can get my CMA, RI and BOCP autographed ; ]? <We will see what Bob has to say here, but one way would be to meet him at a trade show/club meet sometime. They are worthwhile to attend for many reasons.> <<Agreed Scott... and rather than mailing books about... the much better way to meet us, other folks of similar interests. RMF>> Thanks again for the wealth of knowledge you so greatly pass out. By the way I kinda get bummed out when I have completed the entire section of whatever im studying at the time, I mean c'mon, you couldn't have made the refdesfaqs go to 20 instead of 13....totally just kidding!? <All the sections are constantly growing!> Thanks again, J J <Welcome, have fun.>

Re: Finishing touches on refugiums, pipefish, and holes oh my...3/9/09 Thank you Scott for your reply! <My immense pleasure!> Got Mr Fenner's comment as well... <Ahh, good.> I live in Louisville, KY, If there were ever a venue near, I would gladly be there. It would be greatly beneficial to me, as seeing knowledge is easier than reading it sometime ya know! <There will be in time, I am sure'¦.keep an eye out!> It'd be sweet to meet my "idols" too ; ] ! I'd like to ask a couple follow up questions if I may? <Sure, but I do assure you, there are no 'idols' here LOL.> Thank you for clarifying I can go with sch 40 bulkheads <Indeed you can!> and I didn't catch it the first time but I believed I mistyped, I meant to say 1/2" on the glass. <Oh good, that is what I had hoped.> 1/4" would make no sense would it hehe! <Nope, the 3/8' can do, but thicker is better here.> I'm thinking of having it built somewhere else but I want to know what is the "norm" wherever I go. <I would at least get a quote from another builder.> I confirmed that with the sch 80 size holes and thicker pane, price is due to increase! Ugh. <No doubt!> He tried to sell me under the whole " you get what you pay for" ! <You do indeed to a point, but there is no reason for Sch 80, unless he is actually doing the install and something wrong here.> Know of any reputable online custom tank companies or any near KY? <Glasscages.com, I have not personally dealt with them'¦but all I have talked to says the product is functional and nice for the money, just not top notch finish work. They are out of Tennessee I believe.> Ok Mr Scott, if it makes no difference where I have the holes drilled as long as the closed loop is placed lower, can I put all three holes in the same overflow box? <Sure you can, I do this all the time! Just keep the holes reasonably spaced out, the general rule is one hole diameter away from the next hole.> I thought of just using just screened 90's turned towards the top of the tank to adjust water level. <Be aware that this can be loud, ideally you will want the elbow facing down to keep things quiet. This will make for a lower water level without a box.> If I don't I'll use the overflow box so I figured I'd ask. Knowing what gph the {2} 2" bh's are capable of....what size {plug a brand too} pump would you recommend to not maximize flow but still be efficient and quiet? Probably about 4-5' head. <The two 2' bulkheads can flow about 2400 gph combined, you were planning in the neighborhood of 700-1000 gph, so this leaves you with plenty of redundancy here. I would personally look at the Eheim line for the return pump, likely a 1262. For you closed loop the Reeflo line is hard to be for efficiency and noise. Since you are at the planning stage still, do reconsider the use of powerheads over the closed loop, it can save you big bucks on your power bill!> Thank you for linking Josh's article, it will come in handy no doubt! <It is.> I will be using one overflow to the refugium, should the "bleed" side of the tee just be going back draining into the sump? <Yep, just give it a place to go.> Do you know of something, article or diagram what have you, that illustrates/explains the hose barb connection for the flex pipe or spa flex you had mentioned? <Just something like these for vinyl tubing: http://www.flexpvc.com/cart/agora.cgi?product=PVC-Barb-Fittings-Slip-Spigot> And just to be sure, flex pipe and flexible pvc are 2 different things? <We may very well be talking about the same thing'¦but flexible PVC needs no hose barbs, it solvent welds into PVC fittings just as normal pipe does.> Sorry for the ignorance! I think if I continue with the plan of pipefish in the refugium, I'll divide it in half so the pods have some protection, that will still give them roughly 25 gallons a piece, does that sound ok? <It would be cramped for the fish in my opinion.> My wife thinks I might as well be working for you guys with the amount of time I spend on WWM, heee :}. <In time maybe you will!> Thank you once again and it would truly be a pleasure to meet you or Bob at a show! <Yes, do come out to one when you get the chance, there are many people to meet!> Without WWM in general, many of our enjoyments wouldn't exist! Maybe one day everyone will venture near the bluegrass and let Bob know to have his pen ready if so : } !!! <I am sure he will!> Scott, thanks and have a great night! JJ <Welcome, talk soon.><<Am ever more anxious to see ScottV out on the petfish talk circuit... RMF>>

Re: Finishing touches on refugiums, pipefish, and holes oh my...   3/10/09
Hey Scott,
Man, I really have to thank you once again!
<Welcome JJ.>
Do you guys ever get tired of hearing all the nice stuff people have to say about you? Haha just kidding! Every response you give, opens up 10 other questions ; ]. I think I have them narrowed down if you don't mind another barrage?
I will be on the lookout for any nearby shows, etc. I also think you and the crew ARE role models in the saltwater world! I'm going to use sch 40 for price and convenience, thanks again!
<Pretty much the standard for aquarium use.>
I'll have you know that with the next estimate, I'll be inquiring on 1/2" glass! Wouldn't you know the "guy" I've been referring to is the "guy" from Glasscages! I liked a type of glass he can upgrade you to that nobody else I've seen has offered.
<Other shops do offer it also, but I do have to admit the price that GlassCages offers the Starphire at is amazing.>
I'm the type of guy who will ask a question at the LFS I already know the answer to. This way you can kind of rate the info you are getting, you know, deciphering a "bs"er from a straight talker!?!
<Yes, an educated consumer!>
Another estimate is definitely in the works! Ok as far as hole placement, I figured one in each corner would be better for structural integrity?.?.
If I were to put them all in one corner, a hole size apart, a hole size across and down from the edges, would the smaller hole be ok a couple inches down in the middle of them [ kinda like the holes in a bowling ball?]? With them all in the same box?
<Yes, but you do not want the closed loop intake inside the box unless you are putting it through the box. That is you don't want your closed loop drawing water from inside the overflow. You will be riddled with microbubbles in the best of cases.>
To clarify the 90's for "overflows"... I would need them to be like a {n} instead of a {u}, where water is sort of rising up in the tube to fill and fall instead of falling in, kind of sucking?
<Yes, good description.>
Would that insist of the curve of the pipe actually out of the water like Dursos?
<It may a bit, not much.>
I'm picturing a 90 pointed up directly out of the BH then a straight pipe with a upside down U on the end? Gosh I hope that makes sense!
<It does'¦If I may be a bit self serving here. Do take a look at my company, Glass-Holes.com. We have boxes that have all of this built into the box. It keeps it quiet, slim in the tank and looks good.>
I want them to be as quiet as possible! Do you think a box would make it quieter and if so and I go with the box do I just use screens on the bulkheads?
<That will be just as noisy as the upward pointing elbow'¦.and very restrictive on the drain.>
I will take a breath soon!
<LOL, you are fine.>
When you said the Reeflo was hard to "be" for being quiet and efficient, did you mean hard to "beat" ; ]? Just wondering.
<Oh yes, sorry, for sure beat!>
Ok, on to your powerhead comment...whew. I actually had thought before, that since it was only a 75 gallon display that powerheads might be more economical and efficient, needless to say easier too. There are definitely some pros...one less hole I need to have drilled, LESS PLUMBING STRESS {on me and the tank}, and you say cheaper on the power bill!
<Way cheaper'¦my Dart pump used to cost me $35 a month to run, while swapping to some powerheads (the MJ mod type to be exact) cost me a bit over $4 to run and provided more flow. The Dart is a first rate pump, I just wanted to be sure you knew the power cost advantage. Most do not realize that pumps are where the electricity is spent. One may have 400 watts in lighting and 300 watts in pumping, but the pumps run 24/7!>
Plus they would be quieter than the CL right?
I was reading on Steven Pro's powerhead analysis and thought the Tunze 6080's were pumps that could be used for closed loops, those are powerheads huh [I noticed the Eheim you mentioned for sump return was on the list]? If so, they produce the gph fairly cheap it seems, especially if the comparison is correct.
<Hmmm, these do, but that particular article is a bit outdated now, there are far better choices on the market now. The Koralias, MJ mod kits, Tunze nanos all come to mind.>
There are a few concerns that arise as well. Please confirm/deny ; ]. I was thinking 1000gph roughly thru the sump as I stated but also thought of roughly 700gph thru the closed loop, do you think I can achieve that thru {2} powerheads in the display, with it being cheaper on the bill and having no real heat issues?
<Oh yes, a couple of the powerheads listed above and you are there.>
I'll be using 6-8 60 watt t5 bulbs and don't want to use a chiller!
<Well there are no guarantees, it is greatly dependant on your ambient temperature and evaporative cooling. But to also realize that external pumps used for closed loops impart some heat too.>
I wouldn't want more than 2 pHs in there with the return from the sump that I'll be teeing into two LocLines. I was worried about heat generation but too much clutter takes away from eye pleasure IMO. Man, using a couple powerheads would make plumbing a lil easier on me and the tank could be up and running quicker!
<PH do have their pluses'¦.but if you find them unsightly the closed loop is nice too.>
The plumbing is the only thing that gets me down a little bit sometimes haha. So if it were your tank would you go with the 2 powerheads and the sump return split into two loclines over the closed loop?
<That is exactly what I am working on setting up right now my friend!>
If so, what's a good powerhead to go with? Hydor or Tunze?
<Either are fine choices.>
Guess I'll be reading that section tonight...I really never did because of the CL plan. Ok with the piping, would it be better to go with "flexible pvc" for plumbing ease?
<I like it, especially for overflow drain lines, it keeps things quite a bit quieter re water noise inside the line.>
And should I use a smear of silicone instead of using a solvent?
<Silicone on threaded fittings so you can remove them down the road if need be, solvent bond all the slip fittings.>
The reason being if something needed to come apart it wouldn't be permanent. As far as the split refugium, thanks to you I scrapped it. I think either I'll have it all combined and suffer the pod loss, or just set up another tank devoted to syngnathids!
<Really the best way.>
Don't want them to "suffer" for my pleasure. Sorry once again for writing a novel but I can say I honestly have a clue now!
<No problem, good!>
Thanks for the vital help you have given. Trust me it will be put to good use. It would be an honor and I would love to "give back" for all I've taken from this site...everything I know has come directly from all the info on Wet Web Media. I don't have enough hands on experience to be of great assistance to the newbies like myself. It would be a great excuse for me to use on the wife, then she couldn't gripe for all the late nighters on WWM ;] Scott thanks a million. Have a good one!!!
<Very welcome JJ, and thank you from myself and the rest of the crew for such high praise!>

Re: Finishing touches on refugiums, pipefish, and holes oh my...3/11/09
Thank you Scott for the speedy reply! You have my absolute gratitude!
<Welcome and thank you.>
Everything you said made perfect sense but I would like to cover a couple points for your input before I move on. I took a look at your site, looks like you know what your talking bout huh! Do you think the 1500 gph complete kit would house the 3 inch holes if I put them together rather than separate corners?
<It will not, but you can request one that does, it comes out to about an inch longer and ½' or so wider front to back to achieve the flow.>
Of course the pump rating after head loss would be less than the 1500. Is that the only choice, the black covers?
<Blue and clear, other colors too with some lead time.>
As far as the powerheads, do you think the Tunze nanos would serve me well, given what I'm trying to accomplish?
<Yes, a good choice.>
Those MJ mod.s look sick man : ).
<Oh they are'¦.I am from the day (not that long ago) where we would make the things by hand out in the garage.>
On the heat issue, I realize I wont know for sure but your thoughts are appreciated. The room that the tank will be in is in my basement [below ground]. It has no windows. I think it stays the same temp year round but have not confirmed with a thermometer. It is definitely more cool than hot ;) . Between 66-68 probably. I keep my AC on 68ish through the summer anyway. As far as the evap cooling, I had planned on about 85% of the tank top being covered by glass lids under my canopy. I could possibly leave the glass cover [not canopy] off, and utilize the squares/egg crates stuff. And the sump I believe will be topless. Evaporation does help cool the water right?
<It can have a huge impact.>
I could possibly rig up some fans across the surface if you think any of this will help!?
<Fans can help quite a bit'¦.do try running it as planned first, see if heat even is an issue. With an ambient temp in the 60's and your choice in lighting I doubt you will have issues. If you do an increase in evaporative cooling should do the trick.>
I'm liking the convenience and versatility factor, but I'm not sure how much heat the powerheads will distribute.
<Not much.>
How bad do you think 2 phs in a 75 can be? Given the light set-up, do you think there will be a chiller in my future if I go with the phs?
<I think you will likely be fine without one.>
Again, I know its hard to say. Saying all that, would you still have the smaller hole drilled? If I did, it wouldn't be much farther down then the 2 overflows. That way, if I ever did incorporate something to that hole, I wouldn't have to drain much!
<I think it is a good idea. Have it drilled and plug it'¦it gives you options in the future.>
I wasn't sure if I needed to direct the overflow box questions to you through Glass-holes, sorry if so!
<Na, this is fine.>
I'm going to take a look at Moms Fish Supply, at the rest of your stuff tomorrow when I get a chance. Oh yea...I meant to ask, what do you think of the Starphire glass?
<It is nice when you can get it for a reasonable price.>
Thanks Scott for all your help once again. Hey since you said you were working on something similar, we ought to trade a few pictures after they're complete ; ) .
<Sure thing, you can send them along to the GH email if you like!>
Talk to ya soon!
<Keep in touch.>

Re: Finishing touches on refugiums, pipefish, and holes oh my...3/12/09 Hey Scott, <JJ> I just got done looking at your videos, the ones on YouTube too! They're awesome man! You did a good job on em'. <Haha, thanks. We try to make them fun.> What kind of beer was that and what's up with the whole goat thing lol? <I believe it was Fat Tire that day'¦the goat is just an old pic laying around that somehow made it in! Man, you did watch the whole thing!> I'm going to do just as we talked, with the Tunze nanos and the 1.5 inch hole for whatever down the road. I am wondering after seeing the vids if I should just drill the tank myself...OK, now that I'm over that idea, [you made it look easy but if the tank company screws up its not out of my pocket ; ).] <It is easy, but if you are buying new there is no reason to not have the factory drill it.> How hard would it be to match your box with predrilled holes, as simple as doing every step but the glass drilling? <Give my bus partner Mike an email or call from the contact info on the site. He can provide your tank manufacturer with a PDF that shows exactly where to drill.> Knowing my luck something would screw up lol. Asking about that 1500 kit...that was for [2] 1.5bhs right? <Yes.> Do I really need [2] 2 inch bhs if I'm to use powerheads? <No, just keep your sump flow around 700 gph to have the overflow redundancy.> If I went with [2] 1.5 inch bulkheads for the overflow your 1500 box kit should work if I understand correctly!? <Yes.> If not, no biggie you said I could get one custom right? <No big deal.> Do you have any examples of the blue or clear? <Mike may, ask him when you email.> I want one of those shirts too ; ]. Can I contact you on the "contact us" on GH? <Definitely.> I would be ready for a box within a month or 2...I still need to get another estimate, then actually get the tank built and shipped to me. I'm still kind of skeptical of the TN company...and you said that was cheap, sheesh I'd hate to see it anywhere else then! Maybe I should overlook the rants on sch 80 as long as they build what I want with the sch 40's? <Is the route I would go.> Or go with "greener glass" somewhere else lol. <Starphire is great stuff, but by the time you get the tank actually up and going you will be happy with regular glass too!> Guess I'm off to put start getting this all together {the really fun part!} Let me know what your emphasis is on this last little bit. Thanks bro, have good day. JJ <You too JJ, have a good one.>

Re: Finishing touches on refugiums, pipefish, and holes oh my...3/12/09
<Hey JJ!>
What's going on man. Yea I did watch them all! Actually, the videos cleared up blurry areas for me on the plumbing, and the goats are cool!
<Ahh, good.>
I'm going to miss the actual research and planning stages before setting up...its been one fun learning experience.
<I do like that part myself too.>
Hey, I just wanted to let you know, you've been a lifesaver on this project of mine!
<I am happy I was able to help out.>
I'll give Mike a shout tomorrow afternoon. I'll probably call if that's ok.
That pdf will come in handy for the estimates. I'll also need to get a shirt before I start my plumbing...and videos too! Don't know about that fat tire and goats though. I'll keep it bud light and things that don' eat cans lol!
<BL? Hmmm, that may affect your plumbing ;-P>
Thanks once again for the time and advice! Look forward to sharing those pics of the setups. Will keep in touch! Take it easy bro!
<For sure, you too!>

Questions about overflow drain size/location 3/2/09 Hi Crew, <Hey Jim> I'm about to setup a 50g (36x18x20) acrylic reef tank with a 20g sump. Initially we'll be keeping mostly soft corals, but that may (OK, likely will) change down the road, so I'm trying to prepare for higher circulation requirements. <Heee, we all get the bug, go farther!> To this end, the current plan is to use a mag 9.5 as a return pump and tee the return line with a valve to allow controlled bleeding back into the sump to reduce flow through the display tank if needed. <You do mean the return line on the pump I hope.> Using some online calculators, <Total junk in general.> I believe I will have approx. 4.5' of head for the pump, which should result in somewhere around 800gph. <Likely 500 or so in real life.> The tank has a center overflow (photo attached) which is 14" on the long side, 8.5" on the short side and is 6.25" front to back. It has holes sized for 1" drain and 3/4" return bulkheads. <Hmmm....> Based on what I have read, the single 1" drain will not be adequate, <It will not be.> so now seems like the right time to add more, which leads me to my main question: 1) Based on the above info and the photo, how large of a drain bulkhead would you recommend adding, and where in relation to the existing holes would you add it? <You could drill between the holes, a little offset to the front or rear, assuming the tank bottom is not tempered.><<Is acrylic...>> I want the drain to be as foolproof and quiet as possible, but I don't want to drill too many holes in close proximity (or too close to the tank's edge???) if that's a potential problem. <Well, it will be tight, you may get away with it. The rule of thumb is one hole width from the next hole. But for what it is worth, I would just say drill the rear panel inside the overflow box...it just takes all these factors out of the equation.> Next, two related follow-up questions: 2) Assuming the new drain will be sized to handle the entire flow from the pump, should I treat the existing 1" drain as a backup? <Yes, a partial backup at best though.><<Scott... why not suggest enlarging, drilling this out to larger diameter? RMF>> If so, what is the best way to accomplish that? Should it be raised higher? Should it be equipped with the same standpipe arrangement as the primary drain? <Yes, you will want a standpipe on it, just put it at the same level as the other drain.> 3) As long as I'm drilling, is there any reason to add another return line bulkhead if space allows? <If you see yourself having a need for more flow down the road, now it the time to drill it!> Lastly, I just want to thank you for all the help you provide :-) Jim <Welcome, happy to assist. Scott V.>

Re: Curious re... pls see below -- 03/02/09 "<You could drill between the holes, a little offset to the front or rear, assuming the tank bottom is not tempered.><<Is acrylic...>>" Oh definitely. I have yet to see a tempered panel on an acrylic tank! Enlarging the holes would be easy enough here also. My apologies, rushed through and should not have. <Heeee! Happens. BobF> Oh, the question further below really. B "2) Assuming the new drain will be sized to handle the entire flow from the pump, should I treat the existing 1" drain as a backup? <Yes, a partial backup at best though.><<Scott... why not suggest enlarging, drilling this out to larger diameter?>>" <Enlarging these holes is the best solution here, easy enough with acrylic. You can use a regular saw type holesaw used to drill wood for this. You will need a means of centering the thing. One of the easiest methods for the average DIYer I have come across is to drill a hole with the holesaw in a piece of wood, then duct tape the wood in position over the hole. This will act as a template to guide the holesaw as you start to drill the acrylic panel. Once it is started just a bit into the acrylic you will no longer need the wood. Just be sure to drill slow enough as to not melt the acrylic!> Thanks Bob, I have no webmail access though my phone. I have added a comment below. Scott V. <Ahh! Thanks much Scott. Will accrue. BobF.>

Re: Flow and Pump Question 2/28/09   3/1/09  Scott, <Hey Randy.> Thanks for the response and info, but I'm still a bit unsure on the pump size. I have some telling me that the OR2500 will be good for the two 1-1/4 ribbed pool hose lines/drains(running only 10" into sock) from the Megaflow box into the sump and others that say it's not enough. <It is, do realize that most do not recognize that running overflow lines to their limit is a recipe for disaster.> I also hear that the OR 3500 is way to much and I will need to dial it back on the return, also people say that it's to much flow thru the sump??? <Hmmm, it can be managed through the sump, but the lines will not handle the flow.> I am waiting to order my return pump based on these issues? Any more advise will be greatly appreciated!! <The OR 2500 is my 'go to' pump in most applications. Price, reliability and the flow capacity of many setups line up well with this pump.> I am also contemplating on not using the 300 micron filter sock, is it a big help in the full reef. I know it needs attention weekly but I will probably only get to it every 2-3 weeks. Will this be a big issue with the nitrites? <It can be'¦just buy a half dozen or so of the socks (they are comparatively cheap) and swap it every few days. Then just wash the whole lot at once. This make maintenance quick and easy and keeps the nitrate factory to a minimum.> And I have decided to go with the Extreme pro T5's(6bulb) over the Tek for mostly cost reasons and the additional size of the Tek. Thanks again, Randy <Welcome.>

Overflow drain/setup 2/27/09 Hello, Richard here. <Hello, Scott V. with you today.> Really enjoy this site and appreciate the unbelievable amount of information available to us here. <Good! Thank you.> I've been studying/researching my first reef tank for months and through this site and my other reading I've learned a lot but have a couple of questions that I can't seem to get cleared up. <Okay.> I'd like to explain what I'm planning on doing and then if possible get your opinion. I'm going to order a 120 gallon tank and can have it drilled anyway I chose so I want to make a good decision. I'd like to have only one overflow if I can so as to keep the inside as open as possible. I plan on having two 1.5 inch drains installed (actual drain size). Thru my reading here I know that a 1.5 inch drain should have a flow of 700-750 gph, correct? The confusion comes in when I read on reef central and other places that a 1.5 inch drain can supply as much as 1200 gph. I'm confused about which is closer to what I'll actually experience. Can you help please? <Sure, we are correct! In all seriousness, the answers on WWM are based on what really happens, in real life! All overflow sizes are overrated by most for a number of reasons. Over estimating what a pump is actually flowing, allowing siphoning (recipe for disaster), getting numbers off of so called calculators... fact of it is actually testing the things will show anybody that 900 is the max, 750 gph is a good manageable flow most will be able to obtain with typical plumbing.> The 750 gallons or so per hour seems perfect for what for the 40 gallon sump (total capacity) that I plan to use. <Good, this leaves you with 100% redundancy with the second drain.> This would supply my Aqua C EV 180/Mag 7 with enough flow and I would return that over the back of the tank with an external pump. I have read that two overflow drains are the rule of thumb but what would you suggest I do with the second? Run it over the back in a closed loop with manifold? <Hmm, no, keep it as a second overflow drain to keep the redundancy.> It seems like two 1.5 inch drains would blast my sump if they both went into it. <It only drains what is pumped back up to the tank, the pump controls this.> I know I can throttle back on the return from the sump but is this advisable with that much water flow? <Throttling back a pump on the output side is fine within reason...say within 50% or so of the max flow.> Is there a better way in your opinion or am I missing something obvious? <Listed above.> I'm afraid to rely on one drain as I read they can fail. <Can happen.> I know that I can add power heads if I need more flow. I'll give you the type of system (probably should have done that first) that I'm planning if that would help you. 120 gallons/120+lbs live rock/1.5 inch live sand bed/ light fish/shrimp/snail bio-load and then eventually sps/clams when I'm more confidant. 40 gallon sump with refugium, I figure 27-30 gallons actual in the sump? <That or less... if you plan on 750 through the sump, some powerheads for the planned livestock are in order.> Your time is very much appreciated. thanks <Very welcome.>

Oversized drain and noise 2/21/09 Hey guys, hope you're all doing well! <Hello Dave.> Wondering if you can clear up some confusion for me. <Sure thing.> I am about to pick up a standard dimension 120 gallon tank with a single internal corner overflow with two 2.5 inch holes in the bottom. <Wow! A tank with appropriately sized throughputs out of the box for once.> One is going to be used as a drain, and the other for return. I have a 30 gallon sump, and an Eheim 1260 for a return pump. The expected flow out of the sump, taking head pressure into account, will be about 430 gph. <Reasonable expectation.> I have been reading your website regarding plumbing, and have the impression that I should go with the largest bulkhead and stand pipe I can fit (being 1.5 inch) for both redundancy, incase there's a partial blockage, and to keep the noise to a minimum. <Yes, exactly.> I contacted Richard Durso on his web site to ask about his 1.5" standpipes that he rates at 1500 gph, but he encouraged me to go smaller, because of the relatively low sump flow I have planned! <Whoa, red lights, sirens going off. There is no reason to go smaller...this is like saying you need a smaller garage door because your car fits in too easy. And a 1.5" line will flow nowhere near 1500 gph. 750 gph is a good working number, almost 900 gph in the absolute best case scenario with all of the planets aligned properly at 12 noon on the vernal equinox. I am aware his site claims 1500 here and 600 gph out of a 1" line, but these are both far cries from the real world, actual quantified testing. For those that want to see: http://www.dursostandpipes.com/?page_id=14| To get the skinny on what is really going on read here: http://wetwebmedia.com/SystemPIX/PlumbingPix/Oneinchart.htm  this is only about the 1" bulkhead, but the 1.5" bulkheads are way overrated in the industry in much the same way....sorry to be so long winded about this, but there are so many sources out there misleading people about overflow rates that have so obviously never quantified the actual flow.> He said that such over sizing would actually make things louder because a lot of air would be getting sucked into the pipe due to the minimal water, and produce a boiling water kind of noise!? <Hmm, no. The amount of air drawn into the line has nothing to do with line size, it is all about how much volume the water displaces in the line as it moves through.> I could go with the 1.25" pipe he offers, which is made to fit a 1.5" bulkhead, however this goes against everything else I have read, unless I misunderstood. <You did not misunderstand, going smaller does indeed lower your draining capacity, to the tune of 300 gph or so in this case.> Which is it, does over sizing the drain increase, or decrease the noise? What do you recommend? <Keep it 1.5", if you read through many of the online forums, many if not most out there advocate actually making the standpipe itself larger for noise reasons. There is not any validity to this either IMO.> Also, given my two 2.5" holes, how large of a pipe and bulkhead hole would you use for the return...is there any benefit to over sizing this as well, to a 1.5 incher... or should I stick with the more common 1" or 3/4"? <Stick with 3/4" for the flow you are talking about running.> Thanks very much, Dave <Welcome, Scott V.>

Re: Oversized drain and noise    2/22/09 Scott! Thanks for the light speed quick response! <My pleasure.> Hope you don't mind a quick follow up question for my future reference. I had gone with two 2.5" holes on the recommendation of the tank maker, and I figured it provided some future flexibility for e.g.. should I decide to use both holes for drains etc. <It is what I would have chose too.> However, if the return only needs to be 1" pipe, or as you suggested even smaller at 3/4", the second hole could have been drilled much smaller, thus making the overflow a little smaller...IE hogging up less tank space, correct? <You could have, but I would personally consider just using them both as drains. Having that kind of redundancy is the way to go...You could bring the return over the top or even have another hole drilled. But using the 1.5" bulkhead for your return is easy enough, you just need a reducer for each end of the bulkhead and it effectively becomes a larger outer diameter 3/4" bulkhead.> Not that I can change it now, but just wondering if both holes at 2.5" was the correct way to go. <No, it was a good choice, it gives you so much flexibility should you change things in the future.> Thanks again, Dave
<Welcome, have fun, Scott V.>

New 6ft Marine tank upgrade -- overflow question 2/20/09 Hi again, <Hello Jaime.> I am upgrading my tank from a 4x2x2 to 6ftx2ftx2ft with the 4ft as a sump. I am planning on using an Ocean Runner 6500 as a return pump which has a 1 ¼" output to the tank (corresponding hole being drilled either in the bottom or at the top of the back plane - I guess this is a cosmetic issue apart from the siphoning potential. <A balance of the two, yes.> I have calculated (correctly?) that a 50mm return hole would suffice for draining, with a backup 50mm in case of blockage (set slightly higher). Would you think this would suffice? <If you are referring to the inner diameter of the plumbing, yes, it will be more than enough. If you are referring to the actual hole size in the tank you will want to step this up for a larger bulkhead.> If so, are there any rules about both the distance between the holes and the distance from the exterior of the tank i.e. 2 x the hole diameter? <General rule is to keep any hole one hole diameter away from any other hole or any edge.> On a related note, I was thinking of the return spitting in 2. One section to a spraybar, and one section- the clever (?) bit- to a spraybar at the bottom of the tank. This bottom spray bar's holes would point towards a series of perpendicular 2" high acrylic sections attached to the bottom of the tank with spacing of around 10cm. The ends of these sections would be closed by another acrylic horizontal piece. The Live rock would then sit on this and the debris would be blown up through them by the spraybar. Does this sound viable / advisable? (pic attached) <Interesting idea, it surely could be done...though quite a bit of work to do it.> Kind Regards,
Jamie Stokes
<Have fun, Scott V>

Another Noise Issue In 90 gallon, and bubbles, addended   2/9/09 Good morning! <Hello Heidi> I have been reading all last night and this morning trying to find the answers for my problem. Same issue as many others in that the water coming into my sump sounds like Niagara Falls. The water is so turbulent that it's causing millions of micro bubbles. I bought the tank used. It's a 90 AGA RR with 3/4" return bulkhead and 1" overflow. Yep....the dreaded 1 inch overflow. I have an acrylic sump/fuge that I believe is 30 gallons with baffles and bubble trap. I have read all the tips to quiet this baby down and nothing has worked. I am wondering if my issue is that my tank is being powered by a Mag 12 pump. And since I only have a 1 inch drain it's being overwhelmed. I use flex tubing on both return and overflow so I have no way of restricting the pump at this time. So IS it that my pump is too strong? <Yes, a 1 inch drain cannot keep up with the Mag 12 pump.> And if that is the case I could either buy a new pump or somehow rework the plumbing so I can add a gate valve into the return line. <Cheaper to add a valve. Regardless of what pump you use, the valve allows you to set the optimum flow rate for your drain size.><<... Umm, on the discharge side of the pump... NOT the return from the tank... The much better advice here IS to add more drains, drainage. RMF>> I know more flow is better but how do I calculate adequate gph for my tank? <Is generally recommended to provide a 10X tank volume flow rate. In your case, about 900gph. This can be accumulative and can be supplemented with the use of power heads. It's not necessary to provide the entire 900gph through your sump.> Right now the Mag 12 provides 1130 gph at 4 feet. Or am I completely going down the wrong path here and should be looking at ways to disperse the water going into the sump? Overflow is draining into 1" PVC that is 2-3 inches below water surface. I was also contemplating bringing the PVC farther down (almost to the bottom of sump) and using an elbow. Any help you could provide would be greatly appreciated. I have to admit if it stays like this I think I would end up taking it down. That is how loud it is! <You need to control the flow from the pump. Do install a gate or ball valve. Right now, I'm sure your pump is cavitating, and that is what is causing the noise.><<Lowering, submerging the discharge is a good idea. RMF>> Thank you! <You're welcome. James (Salty Dog)> Heidi  

Re: Another Noise Issue In 90 Gallon 2/9/09 Thank you so much. You gave me the information I needed! Especially that flow is accumulative as I was planning on using power heads anyway. <You're welcome. James (Salty Dog)>

Re: More re: Another noise issue in 90 gallon 2/9/09 Bob, Adding the valve to the discharge is what I meant, not worded properly. I can see where it could lead her to install on the drain side. If she responds, I will point that out. I will also suggest adding additional drains, but I'm thinking she is not going to be too keen on emptying the tank and having more holes drilled in the tank, but will also suggest over the tank overflows as an alternative method. Sorry for the SNAFU. James <Keen on doing the retrofit or not, this is really the only sensible alternative IMO... I just do NOT trust single overflow drain lines... especially of too-small/inadequate diameter. Cheers, B>

Re: Another Noise Issue In 90 Gallon 2/9/09 Hello Heidi, Just to let you know, I did not mean for you to add a valve to you drain, but rather the pump discharge side. I see the way I worded it may mislead you into thinking I meant the drain side. Another suggestion is to add another drain or two supplying your sump. Since the tank is up and running, you probably aren't too keen on emptying it and having additional holes drilled and boxes constructed. As an alternate method, you could buy some over the tank overflows, but I would still install a valve on the discharge side of the pump. Cheers, James (Salty Dog)

Re: Another Noise Issue In A 90 Gallon 2/10/09 Yes, I did understand perfectly what you said. <Good.> And since I know my drain is too small anyway I would not want to slow that down any more. But thank you for the return email. <You're welcome.> My plan is to replace the pump. I'm thinking of the Maxi Jet Utility pump as it has an adjustable flow rate. It rates at 750 gph and decreases to 500 at 4'. And if that should be too much I can "dial" it down even further. A nice feature to have if I can't get a gate valve installed. <Yes, it is, but ideally it is best to have valves with unions on both the drain and pump outlet. It does make maintenance easier if a pump has to come out for service or replacement.> Thanks again! <You're welcome. James (Salty Dog)> Heidi

Re: Another Noise Issue In 90 Gallon 2/9/09 With single overflow lines of any type, HOB or drilled....one is just not enough. Human nature is to just flow the thing to max (even with multiple lines), think it will flow more than it will, and restrictions will always occur. Water just ends up everywhere! The answer? Take what you need and double it at least, seriously. Fact of it is larger lines can just pass more crud through without clogging...larger is better, more is better here too! I see an article coming out, and soon. Scott V.

Hi Scott, I did offer this same information to the querior in a separate email I sent out yesterday. You seem to be into plumbing pretty well, have you found a plumbing calculator on the net that is reasonably accurate. In the past, I've used the one on Reef Central, but I do not believe it is accurate but may be good enough to get in the ballpark. Your feelings? Regards, James

No James, I have yet to find a calculator that is at all accurate in regard to overflow lines. Like you say, the RC calculator is just not accurate, much more so at certain flows than others. It is not universally wrong! Scott V.

Well, I take that back. I had not looked at the calculator in years. It is universally wrong! Scott V.

Aaaahhhh.....insane with bulkheads and holes...2/8/09 Dear Mr Fenner or Calfo or both : ] <Hello Jay, Scott V. with you this go round.> I must first thank you for the huge amount of money I'm going to save from the months...and I do mean months I've spent enjoying reading over WWM!!! <Wow, great! Thank you.> What you do for hobby newbies like myself is priceless!!! Now if I may, I have a question re plumbing, more specifically bulkhead/holes. I will be setting up a 75 gallon "light" reef tank! Probably heard that before right...hehe. <Thought that before!> I've decided on everything but the plumbing. The fun part huh?! I'm going to utilize a sump and I'm aware of the constant issues with these so called reef ready tanks, so I plan on having one custom made. Mainly to accommodate appropriate flow for the inhabitants. Plus I want a Starphire glass front. This is where I go nuts! Each time I think I know how I wanna go about it I read something else and second guess my original idea....here's what I'm thinking, I need your most valued opinion before I make my move! <Okay.> I'm thinking I want each drain hole to be able to quietly handle 600gph {so I can keep powerheads out of the water even without the closed loop}. Also be able to handle a closed loop I'll use later on down the road. I figure that'll give roughly 1200gph and would suffice until maybe I could bump it to around 1500 with the later installation of the CL.?.?. I think I want to have 4 holes drilled, 2 on the bottom of both sides. At first it'll be one as a main drain to the sump, one as a slow flow drain to the fuge, the two other holes as returns! <Sure, but do just make the drain to the refugium a full flow throughput, with a tee off to the refugium that you can adjust.> After everything gets settled and things start maturing I will eliminate one of the returns or drains and utilize this hole for the external pump I run the closed loop I eventually plan to install {do you think its better to install this with the initial setup?}. <It is far easier to do it at the start.> The other return/drain I'll still use or just simply "cap", if they can be capped<? <Yep, simply a bulkhead and a PVC plug.> So in your opinion what size bulkheads/holes should I utilize to achieve the flow needed? <Two 1.5' bulkheads will achieve the flow for the overflow, but leave no redundancy. I would either opt for 3-4 1.5' or 2-3 2' for the overflow. 1.5' likely for the closed loop intake/return.> I know I can taper them down as needed and it is best to go too big rather than too small but with all the bulkhead size to hole size ratios it gets confusing. So I'm asking,... if it was your 75 gallon, what would you do? <Three 2' throughputs for the overflow.> Reminds me of that bracelet "what would Jesus do" well they should make one for aquarists, "what would Bob/Anthony do." *Not trying to be blasphemous* <Hmmmm, no. It is just what works.> Sorry for the length of this query but one more question. Do you find it more beneficial to plumb a separate refugium to the same sump with its own little return pump or section off part of the sump as the fuge? <Better/easier IMO to just run it off the main return. If you want a separate refugium, just have it overflow into the sump return.> Sorry for the vague question there, "fuged" either way is fine with me but the thought of figuring out extra plumbing for a separate fuge makes me a little nauseated, so any simplified instruction on how to do so would be fabulous!!! <Just overflow it to the sump to link them together.> I'm sure I speak for others as well as myself when I say thank you and WWM for what you do for the saltwater community. <Well thank you!> If this isn't Bob, can you tell him to post more pics of his diving adventures soon ; ]. Thanks a million! <It is not Bob, but I know he has been working hard posting many of his dive pics, archiving them on WWM for all to see.><<A continuous, and joyous process. RMF>> Jay <Welcome, Scott V.>

Re: Aaaahhhh.....insane with bulkheads and holes... and pb  [R2] 2/13/09 Hello, to whomever I have at the other end this mornin' ! <Hello, Scott V. with you again.> I am sending this email again, I want to apologize if you received the first follow up email but I sent it Monday, and I've had a few problems with others getting my emails this week. So I figure I'll give it another go in case you never received it! Thanks and sorry! <Ah, no problems, did not see the other one, but this one is here!> Hello Scott, thank you for your speedy reply!! <Welcome.> I think I do but let me make sure I got this. First off, I did mean that I would taper it down through the plumbing with an adjustable tee, I realize it probably didn't sound that way ;]. I was wondering which way you thought was more beneficial, making the fuge part of the sump or its own tank? <Six in one, half a dozen in the other. Whichever suits your situation the best. Bigger is the game, if you can fit more with a combo unit, great. If you can fit two separate tanks, fine.> Ok, I'm assuming {uh oh} by redundancy you meant that 2 1.5" bulkheads would do 1200gph but leave room for nothing else? <Exactly, in the neighborhood of 1500 gph for two 1.5" lines....the redundancy pertains to having an extra or two should one line fail, get plugged.> With 3 2" bulkheads for the overflow, 2 for the sump and 1 for the fuge and the 1.5" bulkhead for the CL would I need 3 3" holes and 1 2 3/8" hole? <For most schedule 40 bulkheads these are the sizes.> Could I get away with 2 2" bhs and 2 1.5" bhs with all I'm trying to do? <Yes, a 2" gravity fed drain can handle the 1200 gph, two will leave you the redundancy.> Where is the best place to have the holes drilled, bottom, sides, back? <Up to your tastes, I personally like it through the back to allow for a smaller overflow box. Most tanks in the size range you are looking at cannot be drilled through the bottom due to the use of tempered bottoms, if you want this do be sure to order it done from the factory.> I don't think I really like the thought of being able to see the throughputs or holes. I was going to utilize Durso style standpipes when the plan was for the bottom. Do these type pipes need to be the same diameter as the bulkhead? <Yes, though some advocate for using even larger diameter piping for the standpipe. The argument is it is quieter. Bunk. The same diameter standpipe is fine.> Sorry for all the questions but I want to get this right the first time! <No problem.> Could I incorporate the closed loop from the sump with all the drainage that'll be coming through there with a nice submersible pump in the return section or should I use the 1.5" bulkhead for the closed loop through an external pump? <The latter is how you will want to plumb a closed loop. You can run all your flow through the sump, but too much gets hard to manage in regards to microbubbles and noise.> I don't need any return holes I reckon because I can just run the return/closed loop up the back of tank right? <Yes.> Depending on your answer to the last question, what size pump and plumbing should I use, I look to utilize 6 tees or movable elbows rather in the tank for about 250gph each one to get roughly 1500gph and <1500 gph through six 1/2" outputs would work fine.> I've read somewhere to keep the pvc the same size as the outlets on the pumps, is that true? <A good rule of thumb, until the point you get to the actual outlets. Then choke them down to your output size, I would use the 1/2" here.> Would I need to use smaller pipe for the ring around the top of the tank or the elbows? <Not the ring, but on the outputs themselves....a pump this size is going to have a 1"-1.5" output.> There would be about 4-5 feet of head. Is that an answerable question ;]? <Oh yes!> Thank you once again! If WWM and all the volunteers didn't exist neither would my little slice of the ocean!!! Thanks again... <Welcome, and thank you!> A future happy reefer! <Ahh, good. Do look at a product named LocLine for your outputs. It is cheap and makes adjusting your returns very easy.>

Re: Aaaahhhh.....insane with bulkheads and holes... [R3] 2/15/09 Hey Scott, thanks again for the time you take out of your day, to help people like me, I cant say that enough! <Welcome, it is my pleasure.> If you're ever in Kentucky drop me a line and the beer is on me!!! <For sure, thank you!> Thanks to your help I've decided on what to do but I want to ask a few more "brief" {gulp} questions if I may, then I'll be on my way...until next time of course! I'm pretty sure, if space allows, I'm going to make the fuge its own separate vessel! In saying that, I'll have it gravity feed through a small Durso to the sump. Should the fuge return be from a plain old powerhead next to the display pump in the return section of the sump or rather tee off the return line and use some sort of valve to control flow back to the fuge? <Either can work fine for this, I do personally like to use a separate powerhead for this. I just makes it simpler in my opinion, some think teeing off the return is easier.> If the latter, would that hinder flow, knowing I'll be teeing again for the 2 returns to the display? <It will cost you flow, yes. Another plus for the separate powerhead. Or even just running one of your overflow lines into the refugium and forget about pumping water directly to it all together.> Whoa! Ready for that drink yet? <Sure, I am on my way to Kentucky right now!> How problematic will 1200 or so gph be going through what I plan to be a 40 gallon sump? <It can be handled, I have ran 2000 gph plus through these tanks without issues. Just get creative with baffling if you need to, it is like a puzzle.> That's about all I got room for in the stand. Ok, for the holes I'm to have drilled, I thought of having the 3" holes in the top corners of both sides, of course about 3 inches from the top and side, with the 2 3/8" about 3 inches inward towards the middle, sound good? <That can work fine, do be sure to put the closed loop intake a few inches lower to be sure you will not suck in air.> I find I'm talking myself out of the bottom placement, I've been reading horror stories of the glass cracking near these holes. Even with standpipes, if it cracks at the bottom, waters probably exiting! <For sure!> What are some reasons they crack other than over tightening? <90% of the time it is somebody putting force on the plumbing. Once you have a bulkhead tightened down with a PVC line attached, you now have a great lever to put some forces on the glass it just can't handle.> They will be drilled at the factory!!! <Ahh, good.> The LocLine appears to be exactly what I wanted to use, so that frequent adjustments could be made. Thanks for mentioning it! Bet they'd work well with the CL! <I don't know what I would do without it.> I would also like to utilize flex pipe for most of my plumbing, until the valve/disconnect[s] near pumps and entrances, in your opinion, what ultimately has to be hard plumbed? <Nothing really. The flex plumbing makes the job easier and reduces noise too in many cases.> I've read were it wasn't good with closed loops. <It is fine, reduces vibration transmission from the pump too.> Now let me bother you on my lighting for just a sec. [bartender, one more round please] I was looking into Current's "nova extreme" 8x54watt fixture. Set it up with maybe 5-6 10k and 2-3 actinics. I was told that would be overkill for Zoanthids and mushrooms, which I'd really enjoy keeping. I don't see any real future in stonies but I want to keep it versatile, who knows what the future will bring? Would you tone it down a bit, or does that seem ok? <You can use the 8 bulb fixture. You can always run bluer bulbs, it has the effect of less lighting. Also, some fixtures can be run without all the bulbs in them.> I've also read that the nova extreme 6x54 fixture was more beneficial due to the 6 individual reflectors, the 8x54 has just one main reflector. What's your take on this? <A hot topic, for what it is worth I would just go with the 6 bulb fixture in your case. You will be able to keep just about all you want in a 75 with it.> I think I'm going to encounter the problem of having a 48" wide canopy and needing a 48" light fixture. What gives? <Well, start with measuring the actual inside of the canopy. If it is a sit on top type you may have trouble finding a fixture that will fit. Many canopies will give you a full 48" inside though. And the new T5 fixtures are available in a true 48" too, not 48.5" like many of the older fixtures.> Can you tell me how to avoid this? Ok, I'm nearing the end bro...I swear. Are you the Scott from Glass-Holes? <Yes.> If so, you guys don't sell custom sumps? <Not typically anymore. All our sumps are custom made per the customers needs. With shipping costs nowadays it is just far cheaper to find a local acrylic fabricator for most. There are those that insist we make them a sump anyway, but save some cash and look around in your area.> When I'm ready I'd like to get my boxes from you, do you have a different contact on the site? <Info@Glass-Holes.com> Will you take payments on the shark repellent? ; ] <Hmm, Mike is going to be a little upset with me, but I think I used the last can up diving a few weeks ago....> Thanks again for letting me give you a headache these past few days!!!! My future charges will appreciate it tremendously! Jay <Very welcome, do let us know how it all turns out. Scott V.>

Re: Aaaahhhh.....insane with bulkheads and holes... R3   2/17/09 Scott, thanks man for all the help! <Very much my pleasure.> It'll be a couple months probably [gotta take my time right] but I sure will let you know how it works out, I mean heck, you're basically my tank's godfather haha. <Too funny, I am honored! Do let us know how it all goes.> I'll use that email link when I'm ready for the overflow boxes! <Sure thing, thanks!> Thanks once again to you and all the wet webbies who take the time to help on this FABULOUS website!!!! <I will pass this around to the crew, thank you. Scott V.>

Marine Set-Up 1/31/09 Hi. <Hello Jack> I find your site very informative and many a times have encountered some quite useful information from the WWW. <Is what we are here for.> I'm wondering if you can assist me. I am setting up a 10 gal sump for a 55 gal reef aquarium. I made an overflow box that uses a 1" bulkhead and tubing going to the sump. I plan on using a "Coralife" skimmer rated at 325 gph. My question is on the return pump. I already have a "Quiet One" 2200 pump I plan on using and it is rated at around 300 gph at a head height of 5.5 feet. I think that would be sufficient but I really want to avoid filling my living room with salt water. What are your thoughts on this? <If I'm reading you right, you are thinking that by adding the skimmer with it's pump along with the return pump, it may cause an overflow. The skimmer pump draws water from the sump for processing and the processed water returns to the sump. This will not cause the sump to overflow.> <<Mmm, but a single one inch ID line could easily lead to overfilling the tank should it become blocked... RMF... I'd refer the writer to WWM re Overflows...>> Thanks-- <You're welcome. James (Salty Dog)> Jack

Overflow Sizing 1/7/09 Hey Crew, <David> I was reading through your daily FAQs over lunch break (as usual, great read!) and noticed a common/recurring question that has me concerned. From what I've gathered based on responses, 1" drains should not be trusted with more then 300gph of flow apiece. What concerns me, is that my 2 year old Perfecto 180gal "reef ready" tank came from the factory with bulkhead fittings that are sized to slip 1" (inner diameter) PVC into. I have been running two "1200gph" (at zero head) Mag12s for returning water from the sump, with very direct plumbing with minimal angles, and pumps nearly directly under holes in aquarium. I would be surprised if these pumps are losing over ¼ of their pressure from these straight forward lines (especially considering they are rated at 1100gph at the head height my tank would demand) If they are only producing ¾ flow, that would still be 1800gph which is three times the combined flow I've read on WetWeb responses as appropriate my two overflows. I have had this tank up and running for 2 years without any drainage/overflowing issues, but I certainly don't want a surprise one evening! Am I missing something obvious with calculations? Would Marineland/perfecto truly design a "reef ready" aquarium incapable of safely handling more then 3x total tank turnover through its overflows? <Ah, this could get quite technical, but you have to consider friction loss also. A 90 will give you a loss equal to having an additional 2.25 of 1" PVC, a 45 equal to 1.40, a gate valve equal to 0.6, and a branch tee equal to 6. As you can see, lost gph can add up quite fast. Another factor to consider is the specific gravity of the fluid the Mag 12 has to pump, that will add to the equation as salt water is heavier than fresh and needs a little more power to pump. The pump manufacturers do not state how they arrived at their numbers but I'm guessing the testing was done with fresh water. And then you have the performance curve of the pump to consider which factors around head height, viscosity, etc. All things said, you just cannot compute based on the length of head being used. Another side to consider is the distance between the pump and the sump, this can also add to gph loss, so it is best to keep the pump as close to the sump as possible. I'm betting my money that you are not getting 1100gph at the outlet. If you really want to dive into this, go here. http://www.advancedaquarist.com/issues/jan2003/featurejp.htm> Thank you! <You're welcome. James (Salty Dog)> -David

Re: Overflow Sizing, w/ ScottV's valuable addenda 1/8/09 Thank you for the extremely informative response! <You're welcome.> I completely agree - 1100gph actual output in real-world conditions from 1200gph rated pumps would be absurdly optimistic. I had assumed 3/4 (900gph) per pump was reasonable (based on the wonderful article you've linked in your prior response), but I had not considered salt water viscosity, head loss due to plumbing considerations within the tank, and the possibility that the GPH ratings on these pumps may be flat-out wrong. <I don't know if I'd say they are wrong, just do not know how they were arrived at.> In my particular case, I have 1.25" flex pipe clamped from the 1" PVC screwed onto pumps (actually submerged within sump), up to the 1" PVC mounted directly to bulkheads without any hard bends, gate valves, or any Tees under the tank. <If the flex pipe is the ribbed variety, the friction loss will be even greater.> At least two places I did screw up with my assumptions were that I did not consider Ts and various plumbing aspects (such as the original jointed tubing and spout-heads) that are within the tank, or salt water viscosity vs. fresh water (or whatever is used by this particular manufacturer) for rating pumps. To my original concern, even if my pumps have 50% loss due to head/friction (only total 1200gph achieved out of total 2400gph theoretical output from pumps), that would still be 200% of the flow I'm seeing recommended on responses to others based on my overflow plumbing size (300gph per overflow, 600gph total). Should I just shrug it off as "Marineland/perfecto" magical overflows, or would it be wise to unhook one of the pumps (and lose the safety/redundancy of running two return pumps) to alleviate any potential risks of overflowing? <I'd leave things as they are, if your sump is sized correctly (about 25 gallons), you should be fine. You can find out by multiplying the length x width x height and dividing by 231. This will give you the gallon capacity of your sump. > Thank you yet again for what's always highly informative, educational responses to real-life aquatic issues! You guys (and gals) are awesome! <We thank you for the compliment and you're welcome. James (Salty Dog)> <<A bit to add regarding the 1" bulkheads. Partial/full siphoning and allowing some inches of water to buildup above the standpipe can all have a significant impact on the flow these lines are capable of. The 300 gph number is for a truly gravity fed line with no siphoning. This is far and away the safest, most reliable way to run these. Any other method relies on a balance between the overflow and the return, a recipe for disaster. That being said, anybody with a vessel of measured volume and a timer can test both the 1" line and the flow from the return pumps. Most people would be shocked to know what their pump is actually pumping! Do also keep in mind that running these at the limit also provides for no redundancy. Scott V.>>

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